Ex-police reveal bribes and threats used to cover up corruption in 70s London

BBC documentary to examine incidents that led to setting up of unit on which Line of Duty's AC-12 is based

One of London's most senior police officers, described by a colleague as the greatest villain unhung", was believed to be involved in major corruption in the 1970s but never prosecuted, according to a new documentary on police malpractice.

Former officers who exposed corruption at the time describe how they were threatened that they would end up in a cement raincoat" if they informed on fellow officers and were shunned by colleagues when they did.