An Austin police commander is under a criminal and internal investigation after a woman alleged that he assaulted her at a nightclub in North Austin.

The department confirmed that Cmdr. Jason Dusterhoft has been placed on restricted duty, preventing him from taking any police actions until the matter is resolved.

Dusterhoft's attorneys deny the allegation and say video evidence from the Yellow Rose nightclub on North Lamar Boulevard shows no assault happened.

According to a search warrant affidavit for Dusterhoft's cell phone, the woman told police in late August that she was with Dusterhoft when the two got into an argument and he "grabbed her by the face and mouth with his hand" and then "struck the side of her face with his open hand." She told them Dusterhoft's phone would have messages about the encounter.

The affidavit had been sealed but was made public Monday.

Dusterhoft's attorney, Jason Nassour, said his client "categorically denies that he ever hit, harmed or assaulted her, and the evidence will absolutely confirm that he never assaulted her."

Department officials said they could not comment further because of the ongoing investigation.

District Attorney Margaret Moore said prosecutors got involved in the case hours after the woman's outcry and have been working closely with the department's special investigations unit to determine whether any charges will be filed.