Seven Hong Kong policemen, who allegedly beat up a pro-democracy protester in October, were arrested on Wednesday, reports said. The officers are accused of assaulting Ken Tsang Kin-chiu, who is also a member of the election committee that nominated the region’s chief executive, South China Morning Post (SCMP) reported, citing a statement from the police.

Police officials said that they made the arrests in keeping with the investigation’s progress, SCMP reported. Officials also added that Ken, who is a member of the pro-democratic Civic Party, did not appear to identify the accused and urged him to cooperate in the inquiry.

The group of officers, who were caught on camera on Oct. 15 kicking and punching Ken, had been suspended from their posts until now. The officers have been arrested on charges of "assault occasioning actual bodily harm," the statement said, according to SCMP.

The investigation, carried out by the police force’s Complaints Against Police Office, will seek to find a criminal angle to the case, and the office will reportedly seek advice from the Department of Justice after the inquiry.