Federal officials are investigating the region's top immigration officer, who is allegedly involved with the estranged wife of a man under threat of deportation.

Mario Ortiz (search), head of immigration in Colorado, Wyoming and Utah, is under investigation, said Sharon Rummery, spokeswoman for the U.S. Citizenship and Immigration Service's Northwest region. She declined to elaborate.

But an attorney for Jon Vaupel (search), 42, an Australian citizen, said a private investigator has corroborated her client's claims that Vaupel's wife has a relationship with Ortiz.

It was unclear what, if any, policy or law Ortiz would be violating with a relationship with the man's estranged wife.

A message left Saturday at a phone number listed for Ortiz was not immediately returned. A guard at a detention center in suburban Denver said Ortiz would not be available until Monday.

Attorney Elizabeth Higgins said she has photos showing Stacy Schwab, 41, carrying bags from her car in front of Ortiz's home. Another shows Ortiz leaning into Schwab's car, Higgins said.

Schwab could not be reached for comment, but said in a divorce court hearing that her meetings with Ortiz were purely professional.

Schwab, a U.S. citizen, pleaded guilty to harassment after an altercation with Vaupel last spring.

Vaupel, who filed for divorce, was arrested earlier this year on forgery, assault and harassment charges, according to court records. The case hasn't gone to trial.

Schwab withdrew her sponsorship of Vaupel, who may be deported. He is being held at an immigration detention center.

Vaupel's attorneys said they are concerned about Schwab's alleged relationship with Ortiz and what appears to be an accelerated effort to deport their client.

Meanwhile, Mark O'Regan, who heads the Australian consulate in Denver, said he cannot comment on the case under Australian law.