A prolific sex offender has been jailed for two years after DNA checks linked him to an assault on a 15-year-old boy on a crowded tube train.

Chun Man Ho, 37, of Elmer Gardens, Edgware, was sentenced at Blackfriars Crown Court last Friday after pleading guilty to sexual assault and breach of a Sexual Offences Prevention Order at an earlier hearing.

He was also given an indefinite Sexual Harm Prevention Order and sex offender registration requirements.

The court heard Ho, a registered sex offender with five previous convictions, targeted his victim on a crowded District line train during the evening rush hour on January 27.

The boy became aware of Ho pressing against him in the busy carriage. As the train pulled into Victoria station and the carriage emptied, Ho moved away.

The victim then noticed a substance on his jacket.

Forensic examination of the jacket revealed DNA which matched Ho’s, and he was arrested by British Transport Police officers on February 18.

Speaking after sentencing, Detective Inspector Santiago Sende said: “Ho’s disgusting actions caused his victim considerable distress.

“BTP is committed to eliminating all unwanted sexual behaviour from the rail network, and it is pleasing that this case has been brought to such a swift conclusion.

“The victim did the right thing reporting the incident. I would like to commend him, and encourage anyone else who thinks they have been a victim of unwanted sexual behaviour to tell police.”

Siwan Hayward, TfL’s deputy director of enforcement and on-street operations, said: “The deplorable actions of this individual were inexcusable, and I hope this sentencing reassures our customers that we, alongside our policing partners, take this issue extremely seriously.

"We are determined to completely remove this type of behaviour from our network, and ensure it remains a safe environment for all.”