Some women have been turning to unlicensed sperm donors as they find the cost of regulated clinics prohibitive.

But fertility charities warn they are putting themselves at risk of sexual diseases, hereditary disorders and men who want unprotected sex.

Simon Watson, 41, has been an unlicensed sperm donor for 16 years, donating once a week. He has told the Victoria Derbyshire programme he thinks he has fathered 800 children.

He explains that he meets most of his clients on Facebook - they then have a conversation online before they meet.

The Victoria Derbyshire programme is broadcast on weekdays between 09:15 and 11:00 on BBC Two and the BBC News channel.