Federal prosecutors are reportedly seeking travel records of the former chairman of the Port Authority of New York and New Jersey.
In January, they subpoenaed information regarding David Samson, the authority's former chairman, according to a report late Thursday from NorthJersey.com. The subpoena is part of a probe into a United Airlines flight route between Newark Liberty International Airport in New Jersey and Columbia Metropolitan Airport in South Carolina, the report added.
The route was initiated during Samson's tenure as Port Authority chairman and was halted on April 1 of last year, three days after Samson's resignation, the report said.
News of the subpoena came the same week that New Jersey Gov. Chris Christie faced criticism over his travel and who pays for it. Christie is considering a presidential run in 2016.
United said in a statement it had also been given a subpoena regarding the flight route. "United has received subpoenas for information and is cooperating. United has no further comment," the company told CNBC.
The Port Authority did not immediately respond to CNBC's request for comment.
Columbia Metropolitan Airport is about 50 miles from a home where Samson and his wife spent weekends together, the report added.
There was little demand for the Samson-dubbed "chairman's flight," as federal aviation records show that, on average, it flew at about 50 percent capacity, the website added.
The subpoena also seeks information regarding votes taken by Samson and all communications he had with Jamie Fox, the airliner's former lobbyist and Samson's close friend, who has since become Christie's transportation commissioner, the report also said.
A spokeswoman for Samson didn't provide comment, according to NorthJersey.com. The U.S. attorney's office in New Jersey declined to comment and Fox did not return a call on Thursday, the report said.
Read the full report here.