Social services bosses took legal action after discovering that a man with a learning disability had travelled from England to Pakistan to marry.

Staff at the London Borough of Brent were alerted after the man returned home and his wife made an unsuccessful application to be allowed to enter the UK.

Lawyers for the council asked a judge in the Court of Protection - where cases involving sick and vulnerable people are analysed - to intervene.

Mr Justice Hayden today declared that the man, who has Down's syndrome, lacked the mental capacity to enter into the marriage, following a court hearing in London.

The judge heard that the man and woman were both in their early 20s and was told that the marriage had been arranged by the man's parents.

He said officials should try to get the Islamic marriage, held in a village in Pakistan in November 2012 and solemnized by an imam, annulled.

Mr Justice Hayden said the man could not be identified.

Barrister Alison Meacher, for Brent Council, had told Mr Justice Hayden how staff became concerned after learning of the marriage and the woman's attempt to enter Britain.

Miss Meacher said steps could be taken to try to annul the marriage - even though it had been held in Pakistan under the auspices of Muslim, or sharia, law.

She said an application could be made to the sharia law organisation in the UK or to a family court in Pakistan.

The judge said attempts should be made.

Barrister Ivor Frank, for the man's parents, said the couple had always had their son's best interests at heart.

Mr Justice Hayden said he understood that the couple were trying to ensure that their son would be cared for after their deaths, but he said people who married had to understand what they were doing and added: "For a marriage to be valid it must mean that each of the parties involved has the capacity to understand what the institution involves."