Hackney police station in Lower Clapton Road was the first police station in the country to be fitted out with sophisticated, hi-tech sound-proofed interview rooms,” the Gazette reported this week 30 years ago.

"Both rooms are equipped with expensive twin cassette decks which are designed to end legal disputes over what is said during interviews," the paper informed readers.

The process involved makinng a copy of one of the tapes so that both the police and the legal team of any person questioned had a version, while the other tape was sent to a "tape vault" in Cricklewood, where they were kept for at least two years.

They could only be unsealed on the orders of a judge.

Apparently the system was designed so that the tape couldn't be tampered with.

"All recordings are time-coded to ensure they cannot be edited, and police say the taping puts and end to allegations that confessions are obtained under duress," reported the paper.

The station was bought by the Department for Education for £7.6m in 2013 and was given to a Muslim free school, the Olive School.