MBTA employees at Site T are on administrative leave due to the investigation, according to MBTA Transit Police.

Transit Police Superintendent Richard Sullivan confirmed the investigation in a statement to MassLive on Monday. He also said it was “inappropriate for me to comment on an ongoing investigation.”

“We have become aware of the allegations and are currently awaiting further information from the MBTA on this matter,” a spokesman for Boston Union Carman Local 589 told WCVB-TV. “The MBTA will naturally review any such allegations and we will respond accordingly.” when this process is completed.”