The Police Department said the allegations of mistreatment of the woman whom it described as a riot leader are part of the propaganda campaign waged by hostile news channels.
It however noted that a special order has been issued to look into the claims.
The police say in the footage that has made the rounds on social media and aired by anti-Iran channels, adversaries have made an effort to hurt the feelings of the public by using psychological warfare tactics.
The police stressed that the law enforcement will discipline any officer that violates the laws.
Meanwhile, Fars News Agency quoted a police official as saying that the officer in the video is trying to detain the rioter and take her on a motorbike but later changes his mind because the motorcycle was unfit to do this.
Police say the location where the cops were trying to detain the woman was a square in downtown Tehran. Critics say the video clearly shows that officer has sexually harassed the woman.
Many Iranian cities including Tehran have been the scene of protests following the death of 22-year-old Iranian girl in police custody some four weeks ago.
