A judge has convicted a Toronto police constable of sexually assaulting a masseuse while supposedly inspecting the spa where she worked.

Det.-Const. Mandip Sandhu’s claim he was somehow rendered helpless while the much smaller masseuse forced herself on him and performed oral sex defies common sense, provincial court Justice John Moore said Tuesday.

The married, 37-year-old officer testified in October it was a “lapse of judgment” to submit to a sexual advance from the licensed masseuse at the North York massage parlour in June 2010.

“I was shocked,” he testified. “I didn’t expect anything like that to happen, but I didn’t stop it.”

The 44-year-old woman, whose identity is protected by a publication ban, testified Sandhu made her perform the sex act, and then warned her not to tell anyone.

She said she spat onto a face cloth afterward. The DNA on the cloth matched Sandhu’s, court heart.

Defence lawyer Harry Black argued the masseuse and spa owner concocted the allegations to ward off a police investigation.

But the judge said he accepted her evidence she “was intimidated by the fact that he is a police officer” and unwillingly submitted to his demand for oral sex.

Prosecutor Peter Scrutton said outside court it took a lot of courage for the victim to complain to police. “It’s fortunate that she did. It’s fortunate that the Toronto Police Service and SIU (Special Investigations Unit) conducted exemplary investigations.”

The 11-year police veteran remains suspended with pay. He returns for sentencing April 30.