A United Nations official in a department that promotes "ethics, transparency and accountability" falsified his permanent address to illegally obtain what could amount to tens of thousands of dollars in family allowance and housing funds that normally go to poor and moderate-income citizens in his native France, according to investigators there.

The fraud findings against Bruno Bastet, 40, are contained in an investigation report issued on May 20 by France's Caisse d'Allocations Familiales (CAF), a branch of the French social security system that calls itself "one of the pivots of the French 'social model'" — in other words, a centerpiece of the French welfare state.

The fraud involves Bastet's listing himself, his then common-law wife and two children as residents of a city-owned housing complex in Paris designated for those in need of social assistance. Bastet, a program officer in the U.N. Department of Public Administration and Development Management (DPADM), has actually lived in New York City since 2004, while his former companion told FOX News she and the children have lived in the Dominican Republic since 2005.

Housing benefits of the kind that Bastet has been receiving are based on a complicated formula that involves income, family size and type of rental unit, but they are generally given to French citizens who have income of $17,000 per year or less. They must be living in their homeland.

Bastet could hardly be described as in need of the social assistance reserved for lower-income French residents. Non-American U.N. employees at his P-4 level and experience have tax-free salaries of about $100,000 annually.

With hefty cost-of-living adjustments for New York City residence and other benefits, moreover, Bastet's annual tax-free income is more like $180,000, according to documents obtained by FOX News.

As part of that package, Bastet has taken advantage of a king-sized loophole in United Nations cost-of-living regulations to receive a $2,000-per-month rental housing subsidy, even while other documents obtained by FOX News show he is the long-time owner of a posh Manhattan apartment.

Bastet's apartment is at 140 E. 56th Street in the expensive midtown area, about a dozen blocks from his U.N. office on 44th Street, and a short stroll from the shopping mecca of Bloomingdale's. Apartments in the building have recently been valued at anywhere from $525,000 for a studio apartment to $1.395 million for a three-bedroom unit, according to information obtained from New York City realtors.

CAF officials confirmed to FOX News that Bastet would be asked to return funds discussed in the investigation report, but did not answer further questions. Once a finding of fraud has been made, a criminal complaint can be made in French court, in addition to demands for restitution. Whether such a complaint has been made is not known. Overall, as much as $31,000 at current exchange rates could be involved.

• Click here for a copy of the investigation report and a translation. (Certain details in documents have been redacted to protect privacy.)

Asked to comment on the findings against Bastet, the U.N. declined, citing employee confidentiality.

According to the CAF report, Bastet had for years been listing himself and his common-law wife and two children for family allowance — and subsequently housing-support purposes — as residing at 7A Rue Charlemagne, an apartment in central Paris, not far from the River Seine. In order to receive the benefits, this had to be his principal and primary residence.

As recently as April 20, 2009 — a month before CAF issued its report — the U.N. itself backed up Bastet's false claim about his French address, with a formal letter from the U.N. Department of Human Resources Management to Bastet's Paris attorney, certifying the Rue Charlemagne address as his permanent residence.

• Click here to see the U.N. letter.

According to his common-law wife, Eve de Lengaigne, who has long been separated from him, the apartment complex is specifically designated as housing for those in need of social assistance. In fact, allocation of such apartments in Paris has long been highly politicized; waiting lists are long, and much political string-pulling can be involved in obtaining them.

According to the CAF investigative report, however, French tax records show that Bastet lists his permanent primary residence on a bucolic road on the outskirts of a town named Montgeron, more than a 20-minute highway drive from high-cost-of-living Paris, where the housing subsidy is allocated.

The Charlemagne address is listed as a "secondary residence," on the tax records, says the report, adding that Bastet has not been seen by neighbors at the Paris address for a lengthy period.

Bastet and his common-law spouse, says the report, have not lived together for "many years." The CAF document cites testimony by the common-law spouse, Eve de Lengaigne, that she and her two children — one by Bastet, one from an earlier marriage — have been living since September, 2006 in the Dominican Republic, making them ineligible for housing-support payments.

In fact, Lengaigne told FOX News she left France even earlier, in September 2005. She also declared that Bastet paid her and her children between $6,000 and $7,000 in monthly support money in the Dominican Republic, dating from her September 2006 departure from France until November 2008. He continues to pay roughly $200 per month for their son's schooling, she said. The couple are currently engaged in an acrimonious legal dispute over visitation rights to the son.

Lengaigne, a former flight attendant who is currently unemployed, told French investigators she never applied for housing allowance payments while in France, nor did she receive any.

Lengaigne's name was nonetheless listed as a beneficiary on CAF statements showing housing support payments of roughly $615 per month, in current dollar terms, issued from April 21, 2007 until December 2008. Her name continued to be listed as a beneficiary of family allowance payments of about $170 monthly, at current exchange rates, until February 2009.

Contacted by FOX News, Lengaigne reiterated that she had never applied for or personally received any housing subsidies while in France, or afterwards. Any family allowance or other money allotted to her by CAF for that purpose went into bank accounts controlled by Bastet, she claimed, and she did not see the bank statements after she left France. She told FOX News she assumed her family allowance payments had lapsed when she did not fill out a required annual application for them after leaving for the Dominican Republic.

According to documents supplied to FOX News by Lengaigne, the first housing payment made by CAF in April 2007 was sent to a joint account created by the couple prior to their separation. But the next CAF housing payment went to a new bank account, and was designated only in Bastet's name.

In its investigation report, CAF notes that on April 30, 2007, Bastet and Lengaigne together sent a signed letter to the social welfare agency, asking future support payments of any kind be filed electronically to Bastet's new bank account. CAF obliged.

For the next 20 months, payments of about $785 a month (at current exchange rates) for both housing and family allowances went to the new Bastet account. At some point they began being credited directly to the landlord, a French housing agency, presumably as a credit against the apartment rent.

• Click here to see one of the payment statements.

As the CAF report notes, however, Lengaigne denies she ever signed a power of attorney giving Bastet the right to collect that money on his own, or transfer it to anyone else. In telephone interviews with FOX News, Lengaigne also said she never signed any request to CAF to put money in the new Bastet account, nor did she have any access to it, or records of transactions made there.

FOX News has obtained a copy of the document allegedly signed by Bastet and Lengaigne, which asks that their allowances be sent to the new Bastet bank account, as well as a copy of the couple's common-law marriage "certificate of cohabitation," signed and witnessed at Paris City Hall on November 8, 2000.

• Click here to see the bank account change request and a translation.

Lengaigne's signature on the marriage certificate bears no resemblance to the Lengaigne signature submitted to CAF requesting that future funds go to a new bank account. Nor does the bank request signature resemble Lengaigne's signature in her current French passport.

• Click here to see the mutually signed certificate of cohabitation and a translation.

Why was the new bank account request sent? One possible reason, FOX News has learned, may have to do with a CAF rule change that came into effect the very next day — May 1, 2007.

Prior to that date, child allowance and other CAF payments had to be split between the two parents in the event they divorced or separated. After May 1, however, under the new rules, two divorced or separated spouses could designate only one of them to receive all of their CAF support payments, so long as both formally agreed to the deal.

With a legitimate signed agreement from both parties to route the money to his bank account, Bastet would be able to dispose of the money as he saw fit.

Absent such agreement, the rule provides that the payments had to be split equally.

Asked in an e-mail by FOX News to explain the fact that his common-law wife's signature on the last bank account request did not match her signature on other official documents, Bastet, replying through an attorney, declined to answer and cited "active litigation," presumably with Lengaigne, as the reason.

Bastet also declined through his attorney to discuss his housing subsidy, his Paris or New York residential addresses, or his ownership and possible rental to tenants of a New York apartment, citing the same reason.

The attorney further requested that FOX News refrain from publishing a copy of the bank account change request signed by both parties, which was attached to the French fraud investigation report, claiming that in Bastet's view it had been "wrongfully disclosed."

The U.N. benefits loophole that allows Bastet to claim a rental subsidy in New York City even while he owns an apartment there is not something that the U.N. loudly broadcasts either.

According to a spokesman for U.N. Secretary General Ban Ki-moon, such subsidy payments are perfectly legal, provided employees are not living in the property they own. Under U.N. rules, employees can get subsidies for rental accommodation — paid for by U.N. contributors like the U.S.— even while they build a real estate portfolio in the same city where they rent a dwelling.

The only U.N. employees barred from receiving the rental subsidy are "staff who live in their own home or who do not pay rent for their dwellings," according to deputy U.N. spokeswoman Marie Okabe.

According to the U.N. Secretariat's proposed budget for 2010 and 2011, the U.N.'s human resource department expects that about 840 U.N. headquarters staff members will receive a rental subsidy.

The U.N. declined to provide FOX News with the number of its employees who are enjoying the loophole benefit. Nor did it provide Bastet's New York City rental address for subsidy purposes, citing employee confidentiality.

George Russell is executive editor of FOX News.