A Toronto police officer has been charged with sexual assault in connection with an incident that is alleged to have taken place in his cruiser this past September.

According to the Special Investigations Unit, the officer encountered a 27-year-old woman near Wellington Street and Blue Jays Way at around 1 a.m. on Sept. 24 and proceeded to drive her to her residence.

The SIU alleges that at some point during that drive the officer sexually assaulted the woman.

In a news release issued on Wednesday, the SIU said they have “reasonable grounds to believe the officer committed the criminal offence of sexual assault.”

According to Police Chief Mark Saunders, the officer has been suspended with pay pending the outcome of the criminal proceedings against him.

“It will take its course. The SIU has done their investigation and based on the investigation they have put together what they believe is enough evidence to warrant laying a charge, which is what they have done,” he said.

Saunders was asked by CP24 about whether there are any TPS policies around officers giving a drive to a member of the public; however he did not directly answer the question.

Saunders also refused to answer a question on how the SIU was first alerted to the alleged sexual assault.

"I don't know who initiated it. What is important is that the right thing was done based on evidence," he said, noting that it would be inapprorpriate for him to comment on a SIU investigation.

Sgt. Christopher Heard is expected to appear in court at Old City Hall on April 14.

According to public sector salary disclosure data, Heard earns $144,552.72 a year as a sergeant with the Toronto Police Service.

The filing of sexual assault charges against police officers is relatively rare. The SIU says that four officers from across Ontario were charged with sexual assault in 2015.

The SIU investigates incidents involving police where there has been death, serious injury, or allegations of sexual assault.