A rental car used by two 9/11 hijackers on the eve of the World Trade Center attacks remains shrouded in mystery, the Kennebec Journal reports.

Mohamed Atta and Abdulaziz Alomari rented a 2001 Nissan Altima in Boston on Sept. 9, 2001, and drove it to Portland, Maine, where they abandoned it before boarding a flight to Boston’s Logan Airport, where they rendezvoused with the other 9/11 terrorists.

Shortly after the 9/11 attacks, the Altima became the subject of an intense police inquiry as investigators anxiously sought clues as to the nature and extent of the terrorist conspiracy. The vehicle, however, was subsequently lost in a mire of bureaucracy as federal agents equivocated on what to do with it.

Special Agent Gail Marcinkiewicz, a spokeswoman for the Federal Bureau of Investigation in New England, initially said that FBI agents returned the vehicle to its rental company, Alamo Rent A Car, after having thoroughly swept it for evidence.

Further queries by Marcinkiewicz, however, turned up a different story: FBI officials had maintained possession of the vehicle as evidence and had reimbursed the rental company.

Marcinkiewicz would not say whether the car has been retained or destroyed, the Kennebec Journal reports.