Imbert's role in interrogating the Guildford Four, convicted for the Guildford Pub Bombings of 5 October 1974, came under scrutiny after the four were released from jail in 1989. Lord Chief Justice Lane described the police investigation of the Guildford Four as a sequence of false confessions and police deceits. Imbert claimed to have believed the suspects' “confessions” which were made during an interrogation where they were subjected to violence and threats.