The integrity and success of police investigations and the rights of suspects in cells are under threat from a new law which allows chief constables to replace custody sergeants with "cheaper" civilians, it was claimed last night.

Two clauses relating to the "civilianisation" of the custody officer's role were passed on to the Statute Book as part of the Serious Organised Crime and Police Act, which established a new agency to tackle major gangsters.
But the law has alarmed critics, ranging from rank and file officers to the Law Society, who fear that the authority and expertise of custody sergeants - a pivotal role carried out by seasoned sergeants as "gatekeepers of the criminal justice system" - will be eroded.