A Londoner who falsely imprisoned a sex worker at his flat and raped her multiple times has been jailed for 12 years. Ahad Ali, 21, of Sidney Street, east London, put a knife to the escort's throat when she visited him on 13 February.

Ali booked the woman, who was in her 40s, through an online escort agency. She arrived at his flat at 9pm but once inside he pushed her into his bedroom and locked the door.

He then raped her four times at knifepoint. He grabbed her by the hair and threatened to kill her unless she did exactly as he said.

But the sex beast made the mistake of leaving the room for a short period of time and the woman was able to call a taxi driver on her mobile phone.

She screamed for help as Ali came back into the room and ripped the phone off her.

The taxi driver instantly called the police who rushed to the flat and forced their way in. Ali tried to escape by jumping from a seventh storey window.

As a result of the fall, he suffered a fractured arm and leg. After spending ten days in hospital, Ali was arrested and charged.

"Ahad Ali is a predatory individual who targeted a vulnerable female. This was a premeditated, violent attack that involved the use of a large knife to threaten the victim," said Detective Constable Stav Georgiou-Moran, who led the investigation.

In police interview, Ali claimed the victim had made up the allegations but he was convicted by a jury on 25 August. He was found guilty of four counts of rape, one charge of false imprisonment, one charge of threats to kill and one charge of sexual assault by penetration.

Officers from the Met's Child Abuse and Sexual Offences (CASO) Command built up a strong case against Ali after taking statements from the victim and the taxi driver. Mobile phone analysis was also used to back up the victim's account.

Georgiou-Moran said: "I would like to praise the courage and bravery of the victim in giving evidence against the defendant. Anyone who has been the victim of sexual violence is advised to tell someone they trust or inform the police."