Updated

An aide to Senate Majority Leader Harry Reid repeatedly lied to federal immigration and FBI agents and submitted false federal documents to the Department of Homeland Security to cover up her illegal seven-year marriage to a Lebanese national who was the subject of an Oklahoma City Joint Terror Task Force investigation, FoxNews.com has learned.

Diana Tejada, Reid’s Hispanic Press Secretary, admitted to receiving payment for “some of her expenses” in exchange for fraudulently marrying Bassam Mahmoud Tarhini in 2003, strictly so he could obtain permanent U.S. residency, according to court documents.

Tarhini, now 37, was held in jail and at an immigration detention center in connection with his 2009 indictment on felony charges, documents show. He pleaded guilty to entering a fraudulent marriage to evade immigration laws — a Class D felony — in November 2009, and he was deported in March 2010.

Tejada, now 28, was never charged for her role in the crime.

“We did not charge the woman, and of course we don’t discuss the reasons we don’t charge people,” said Bob Troester, spokesman for the Western District of Oklahoma U.S. Attorney’s Office, which prosecuted the case, which began as an FBI investigation out of the Oklahoma City Joint Terrorism Task Force.

“There’s multiple factors that go into charging decisions. She wasn’t charged and we can’t go beyond that.”

Immigrations and Customs Enforcement would not comment on why it took five years to investigate the couple's marriage.

As recently as five weeks ago, on Sept. 21, 2010, Tejada appeared as a guest on a Spanish-language radio program in her official capacity as a spokeswoman for Harry Reid.

Monday evening, Reid’s spokesman Jim Manley said Tejada was no longer employed by Reid’s office. When asked when Tejada left Reid’s services, the spokesman had no comment.

Manley provided this statement to FoxNews.com:

“Our office was not previously aware of these allegations and, following an internal investigation, the staffer at issue is no longer with our office. The conduct alleged, which took place several years before the staffer worked for Senator Reid, was clearly wrong. But the bottom line remains that this story was a desperation measure by partisan Republicans, who have stooped to slinging mud about junior staffers to score points in the waning days of her campaign.”

In court documents, Tejada, who was also the Press Secretary of Hispanic Media for the Senate Majority Conference Committee, is referred to as “an uncharged coconspirator in the crime of perjury, filing false immigration documents, the crime of sham marriage.”

According to interviews and court records obtained by FoxNews.com, Tejada knowingly filed false documents with the Department of Homeland Security’s U.S. Citizen and Immigration Services; lied in in-person interviews with ICE and FBI agents; and submitted fraudulent visa application affidavits and marriage license documents — all in attempt to use her status as an American citizen to get Tarhini permanent residency.

As a result of her actions, according to court documents, Tarhini was able to obtain a work permit.

“I don’t honestly know the reason why they chose to prosecute Bassam and not her,” said Jeffrey Byers, Tarhini’s criminal attorney.

“I don’t think they could’ve prosecuted the case without one of the two of them saying something, but I suspect they chose to work with the American citizen other than Bassam.”

A Justice Department source familiar with the investigation said:

"As exhibited in the court documents, the case prosecuted by the U.S. Attorney's office in Oklahoma City was a straightforward case involving two individuals who entered into a fraudulent marriage during college in order for one to evade immigration laws and obtain lawful residence."

Tarhini entered the U.S. in 2000 on a student visa to attend Oklahoma City University, where Tejada was also a student. They became friends and married in September 2003 so he could avoid compulsory service in the Lebanese National Army, Tejada later told officials. She was 21 years old at the time; he was 30.

Click here to see a copy of Tejada and Tarhini's marriage certificate.

Two months after their marriage, Tejada submitted an affidavit sponsoring Tarhini’s request for adjustment of status, affirming on his I-485 application for a green card — under penalty of perjury — that she was his wife.

Court records show that Tejada signed numerous affidavits fraudulently representing her marriage, including forms documenting her financial and employment information along with a signed obligation to support Tarhini.

As part of the process, documents show, she and Tarhini attended an August 31, 2004, meeting at Citizenship and Immigration Services in Oklahoma City, where they misrepresented their marriage to immigration officials.

The next year, Tarhini stayed in Oklahoma while Tejada moved to Washington D.C., where she began working as a spokeswoman for the National Council of La Raza, court and public records show.

In 2008, five years after he filed his visa application, Tarhini filed a suit against ICE officials to force a decision regarding the application — a strategy commonly employed when visa decisions appear to be taking an inordinate amount of time.

In 2008, sources with knowledge of the case told FoxNews.com, the FBI — working with the Oklahoma City Joint Terrorism Task Force — sent what’s called a collateral request to ICE, asking them to track down Tejada to interview her about Tarhini.

At this point, Tarhini was a subject of interest in an Oklahoma JTTF investigation, sources said.

In May or June 2008, a source told FoxNews.com, Tejada was interviewed by ICE and FBI agents in Washington, and she maintained that her marriage was legitimate.

In October 2008, Tejada began working for Reid.

On Nov 3, 2008, ICE and FBI agents re-interviewed Tejada in Washington, according to documents and interviews.  This time, sources said, agents presented a slew of evidence against her and Tarhini, and Tejada broke down and confessed that her marriage was a lie, carried out to get Tarhini U.S. residency.

According to court records, she also told authorities that she and Tarhini had never dated nor consummated their marriage.

She told officials that she and Tarhini had discussed divorce, but they agreed to wait a while longer — until December 2008 — to see if his visa would be approved, records state.

In the presence of the federal agents, Tejada withdrew her visa petition for Tarhini, stopping his application to become a permanent resident, and signed a sworn affidavit saying that the marriage was a sham.

Tejada, according to sources with knowledge of the meeting, expressed concern about her job and said she was worried about Reid's reaction to her sham marriage.  The federal agents told her she had an obligation to tell Reid, and sources said they believed she would inform her boss.

The highest level of management inside the Department of Homeland Security was aware that she worked for Reid, multiple sources confirmed, and following protocol, the majority leader should have been informed of the investigation through those channels, as well.

But in July 2009, when an ICE agent testifying at Tarhini’s preliminary deportation hearing was asked specifically about Tejada’s employer, the agent did not say it was the U.S. Senate.

ICE Special Agent Rebecca Perkins: “Currently she is employed with the — a Hispanic center organization.”

Tarhini's Defense Counsel, Jeffrey Byers: “Is that La Raza? Does that sound familiar?"

Perkins: “I don’t know.”

Byers: “It’s a — it’s a — it's something that is a public service group for the Hispanic community. Is that a fair statement, or something to that degree?”

Perkins: “Yes”

According to sources with knowledge of the November 2008 meeting, Tejada also told ICE and FBI agents that she was concerned about some of Tarhini’s associates, including the best man at her wedding, a Pakistani national named Amer Awli, whom she described as “very secretive.” Awli's current whereabouts are unknown.

Following Tarhini’s arrest in 2009, he was interviewed by FBI agents who sources say asked about his ties to extremists groups. Some sources said they determined he did not have ties to any terror group, but other sources close to the case said that could not be ruled out.

“Not all of my cases involve the FBI,” said Tarhini’s immigration attorney, Timothy Lee Cook. “Certainly, there was something out there that caught their attention.”

When asked what that might be, Cook said:  “FBI’s not going to tell anybody that. And believe me, I asked.”

FBI spokesman Paul Bresson told FoxNews.com via email, “We have no comment.”

ICE provided details of Tarhini’s deportation but referred additional questions to the Western District of Oklahoma's U.S. Attorney's Office.

On March 20, 2009, Tarhini’s visa application for status as a lawful permanent resident was denied due to fraud and misrepresentation of his marriage to Tejada, court records state.

That same day, Tarhini was administratively arrested by ICE "due to failure to maintain his non-immigrant student status and fraudulent marriage," court records state. "He was no longer attending the Oklahoma City University, thus violating his immigration status."

In August 2009 Tarhini was indicted on two felony charges: Entering into a marriage to evade immigration laws, and subscribing to false statements.  As part of a plea deal last November, he pleaded guilty to the first charge, and the second was dropped.

Tarhini was sentenced to time served and three years' supervised release. ICE spokeswoman Gillian Brigham confirmed to FoxNews.com that Tarhini was “removed” from the U.S. on March 3, 2010.

Tejada made $52,451.60 last year working for Reid.

Last month Tejada spoke in her official capacity as Spokesperson, Office of Senate Majority Leader Harry Reid, as a guest on a Spanish-language radio program’s immigration-themed special on the DREAM Act, which included a section in which the host answered listeners’ questions “about the do’s and don’ts of applying for residency and naturalization.”

Tejada filed for divorce, “alleging incompatibility,” on March 16, 2010. The divorce was finalized on July 6.

Tejada did not return requests for comment on this article.