A custody detention officer (CDO) has been arrested on suspicion of sexual touching, misconduct and cyberflashing.
The officer, based at Bolton Police Station, was arrested on Sunday and has been suspended from Greater Manchester Police (GMP).
The alleged misconduct was towards a woman who was acting as an appropriate adult for a person who was in custody.
A complaint about the officer was made in June, relating to alleged sexual misconduct that began in May.
CCTV footage from the police custody suite has been seized, police said, along with other digital material.
The CDO is on pre-charge conditional bail as of Tuesday evening and the alleged misconduct has also been referred to the Independent Office for Police Conduct (IOPC).
As detectives gather statements from “all relevant parties” the force said they made a voluntary referral to the IOPC “as to the decisions and speed of action taken in response to the allegation made”.
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GMP added they had offered the alleged victim support.
The allegations come in the week where Dame Vera Baird’s report into GMP treatment of people in their custody is due to be published.
The inquiry was commissioned after a Sky News investigation last year.