Story highlights The suspect began working as a private security guard in 1992, the Port Authority says

He used the identity of a man killed that year, the authority says

The TSA says it's up to private companies to verify identifies of employees

The NYPD says it has nothing linking the man to any investigation of the 1992 death

A man who supervised more than 30 private security guards at Newark-Liberty International Airport is accused of being an illegal immigrant who took the identity of a man killed 20 years ago, the Port Authority of New York and New Jersey said Monday.

Bimbo Olumuyiwa Oyewole, 54, began working as a private security guard in 1992 while allegedly using the identity of Jerry Thomas, a man who was killed earlier that year, according to Steve Coleman of the Port Authority.

Coleman said Oyewole is an illegal immigrant from Nigeria, but passed numerous background checks with the New Jersey State Police and Border Protection. An anonymous tip several weeks ago helped investigators build a case, Coleman said. Oyewole was arrested at his home in Elizabeth, New Jersey, on Monday and charged with identity theft.

Details of Thomas' death in 1992 were not clear Monday but the New York Police Department said it had no information linking Oyewole to any investigation.

Oyewole worked at four private security companies over the last 20 years, most recently with FJC Security since 2003, and had access to various secure areas of the airport including the runways, according to Coleman of the Port Authority.

A woman who answered the phone at the security company Monday said the company could not release information on any employee without the permission of the employee.

"The individual in question was not a TSA employee," the Transportation Security Administration's David A. Castelveter told CNN Monday. He added that the TSA vets security-cleared airport workers against terrorist screening watch lists but "it's the obligation of the employer to verify each employee's identity, employment eligibility including legal status, and to verify that the employee is using valid, legitimate identification."

It was unclear late Monday when Oyewole will appear in court, or whether he had retained an attorney.