A mentally disabled woman who is a wife in a polygamous Islamic marriage is unable to make decisions about having sex, a judge has ruled.

Mr Justice Mostyn was asked to consider whether the woman should leave a care facility and return home.

Her husband, who is also married to another woman, had wanted her to be cared for at her home in London.

He had said it was his right to have sex with his wives - providing they had the mental capacity to consent - and said it was their duty to submit.

The judge, who said the polygamous marriage was valid under Islamic law but invalid in the UK, concluded that woman did not have the mental capacity to "make the decision to have sex".

And he said it would not be in her best interests to return home.

Detail has emerged in a written ruling by the judge following a hearing in the Court of Protection - which analyses issues relating to sick and vulnerable people - in London.

Mr Justice Mostyn had been asked to make decisions by the London Borough of Tower Hamlets, which has responsibility for the woman's welfare.