A woman walking home from a Christmas party was followed for miles before a frightening attack that ended when a passer-by stepped in.
Hossein Mohmoudi, 37, has been jailed for 11 years for attacking a 43 year old woman in east London.
The attack happened in December 2024 as she was walking home from a Christmas party.
He followed her for about three miles, from Whitechapel to Stratford, before attacking her in an alleyway.
A cyclist came to help and ended the attack after about 27 seconds.
At Snaresbrook Crown Court, Mohmoudi denied the charge.
The court heard that he had messaged a fetish website before the attack.
He said this was to practise his English.
The judge rejected his account and said the evidence against him was overwhelming.
The judge called him a dangerous sexual predator.
She said he showed no remorse and that the victim suffered serious psychological harm.
The court also heard that he had followed other women in the past and had been involved in harassment.
On top of his jail term, he will be on an extended licence for four years.
He could also be deported after he serves his sentence.