The father of a young man accused of preparing to go to Somalia to join militant Islamist group Al-Shabaab has revealed his son had been in a mental health hospital for nearly two years.

Trevor Mulindwa, 20, of Hallowell Close in Mitcham, was charged last week under the Terrorism Act with plotting to join the militants.

May 21: Mitcham man, 20, charged under terrorism act with preparing to go to Somalia to join Al-Shabaab

Speaking at his family home in Mitcham, Mr Mulindwa senior said: "The boy has been sick for quite a long time. We are just learning the story.

"He’s been in the hospital for almost two years."

He said his son has spent most of his adult life in Springfield Hospital in Tooting, adding: "The police have got the information.

"We haven’t got much information about this. He was here one month ago and then they took him again."

The family are understood to be Roman Catholics and Mr Mulindwa said he does not have Somalian heritage.

When the Wimbledon Guardian approached the family on Thursday, they did not even know their son had been charged with the offence.

Appearing calm but confused about the accusation, he said: "You know these kids, they tell you nothing once they are 18."

He said the family has been restricted from visiting their son very often in hospital.

A neighbour, who did not want to be named, said: "I think it’s probably just a childhood rebellion. I don’t think it’s serious."

Al-Shabaab is a militant group responsible for a spate of terrorist attacks in Africa - including last month’s violent shootings at a college in Garissa town - where 148 students were killed.

Mulindwa is due to enter a plea at the Old Bailey on Friday, June 5.