A man has been jailed for subjecting a teenager to a terrifying and prolonged sexual assault, during which he threatened to kill her.

Sherwan Amin, 20, of Coombes Road, Dagenham, attacked the girl in her home in New Malden last October.

The ordeal lasted a total of three hours and 20 minutes, Kingston Crown Court heard yesterday.

Prosecutor Oliver Renton told the court Amin held a knife to his victim's throat and said: "I want you to suffer your whole life."

He also told her: "I'm going to kill you."

When his victim bit him in an attempt to escape, Amin bit back - injuring the teen's arm and cheek.

She said in a statement: "Because of being attacked I feel unguarded and will not let people close to me again.

"I'm scared of this happening again.

"He has ruined my confidence and trust in other people."

The teen's A-level results fell by two or three grades in each subject from what was expected, Mr Renton said.

Defending, Christian Wasunna said Amin was on an "emotional rollercoaster" following the death of his grandmother, with whom he had a close relationship.

He added: "He is extremely remorseful about this.

"He is a man of previous good character and he knows that he has lost that now.

"He is determined to take steps to ensure he does not commit any offences like this again."

Amin returned to the victim's home the following day.

He smashed the front window and a TV with a hammer, and stole a laptop and a phone.

Amin admitted two counts of sexual assault on the day of his trial last month, and pleaded guilty to burglary in January.

Recorder Sarah Plaschkes QC sentenced him to a total of three years and 10 months in prison.