The MBTA police officer accused of posting a photo online that mocked a man who defecated on the floor of a T station was placed on administrative leave Monday, officials said.

Transit Police Officer Ashley Carlson, 31, allegedly posted the photo on Facebook. The photo shows a man curled up on the floor beside a wheelchair with his pants down just above his knees.

Carlson, an eight-year veteran, has been placed on administrative leave pending the investigation, Transit Police Superintendent Richard Sullivan said Monday.

“I have seen the photograph; it is very concerning to me,’’ Sullivan said.

Sullivan said that if the investigation determines that Carlson posted the photo, the department would be “disappointed.’’

The department’s social media policy prohibits officers from posting anything “that would bring discredit to yourself or the police department,’’ Sullivan said. “It would be viewed as a violation of our policy.’’

Sullivan said the victim was identified, and that he had received care from Boston Emergency Medical Services. Sullivan declined to comment further.

Above the image posted on Facebook were the words: “You think your job is [expletive]!!! This is what we responded to this morning. This guy is well known to police and has a lengthy record. I don’t get paid enough to deal with this [expletive] . . . literally and figuratively!!!’’

Carlson, who made $64,917 last year according to MBTA police records, has not responded to requests for comment. Sullivan said that if investigators determine that Carlson posted the image, they will also seek to determine whether she did so while on duty.

Sullivan said that “the vast majority of Transit Police officers are hard-working, dedicated professionals. They do a tough job, day in and day out.’’

Civil rights leaders criticized the officer’s alleged actions on Sunday, calling the post “disturbing.’’

Jan Ransom can be reached at jan.ransom@globe.com. Follow her on Twitter at @Jan_Ransom.