BOSTON (CBS) – The MBTA is investigating reports that a T worker took pictures under a woman’s skirt.

A woman says the employee snapped photos last week while using an escalator at South Station.

In a tweet, the witness wrote, “Just saw #MBTA #SouthStation employee take picture w/cell phone under a girls skirt on escalator! Disgusting!”

An MBTA spokesperson would only say the investigation is ongoing.