Cops set up a drugs hotline for Holloway, urging called to “squeal” on dealer neighbours.

The confidential phone line was the first of its kind in the borough, with police trying to tackle Holloway’s heroin and cocaine problem.

In 1987, 400 people had been arrested for possession, with 75 drug pushers caught.

Det Insp Edward O’Connell said: “A lot of people don’t want to be seen talking to the police. The feedback was that if we set up a confidential phone line, they would give us information on pushers.”

Meanwhile, a children’s home was closed by social service bosses after a “violent incident”.

Children from the home in Highbury New Park were sent to other homes in the borough.

Islington Council refused to reveal details of the incident, but at least one member of staff was reported to have been injured when fighting broke out during a drinking session. The town hall ordered an internal investigation.