NASHVILLE, Tenn. -- The Tennessee Highway Patrol is facing another scandal.

Video: I-Team: Troopers Investigated In Steroid Probe

I-Team reporter Jeremy Finley reports that state troopers are being investigated in a steroid probe that has already ensnared three Metro police officers.

A THP spokeswoman confirmed to Finley that an internal investigation is under way into allegations of troopers using or selling steroids.

The investigation comes two weeks after the I-Team spoke to Metro Police Chief Ronal Serpas. Serpas indicated in the interview that his officers weren't the only ones being investigated.

"Currently, three members of the police department and members of the community are under a joint police and federal investigation," he said.

It was unclear at the time that members of the community Serpas may have been alluding to also included state troopers.

The three Metro officers have been temporarily stripped of their badges and guns during the investigation. The THP spokeswoman said no troopers have been taken off the streets while the allegations are being investigated.

The Drug Enforcement Agency, which is heading the investigation, said only that it has a large investigation under way and will not say what role -- if any -- the officers and troopers played.

The Office of Professional Accountability for the THP is investigating the allegations.

The spokeswoman for the THP said she did not know if any other agencies were investigating.

A trooper was charged last year and accused of exchanging sexual favors with an adult film star to get her out of a ticket. In 2006, the Gov. Phil Bredesen ordered sweeping changes to the force after troopers were discovered with criminal backgrounds and were also accused of getting promotions for political contributions.