A 58-year-old MBTA bus driver has been taken out of service while the Boston Police Department and officials from the T investigate the circumstances of a bicycle accident in Allston that killed a man in his twenties.

“A Route 57 bus operator has been taken out of service while police investigators work to establish facts in this matter,” according to T spokesman Joe Pesaturo. “[The driver] is 58, and he has been with the T for six years.”

According to reports, witnesses said an MBTA bus may have been involved in the accident, which happened on the corner of Harvard and Brighton Avenues on Monday evening, just after 6 p.m.

Jake Wark, a spokesman from the Suffolk District Attorney’s Office, said the cyclist was killed but no charges have been filed at this time.

“It is still under investigation,” said Wark, via e-mail to BostInno.

Wark did say, however, it was a “bus and [bic]cycle collision.”

The roadways were closed down near the accident, right outside of Redneck’s Roast Beef in Allston, while investigators tried to determine what happened.

According to BostonBiker.org, a community biking blog, the cyclist may not have been wearing a helmet at the time of the accident.

Photographer Scott Eisen took photos from the scene immediately following the accident.

 In June, Boston Police and MBTA Transit Police investigated the driver of a T bus after a 28-year-old Boston College graduate student was hit and killed while riding her bike on Huntington Avenue.