The 19-year-old lover of Iris Robinson falsely told her he was suffered from testicular cancer to get out of the relationship, it has been claimed.

Kirk McCambley, now 21, was bombarded with emails and love letters from the 60-year-old MP, the Irish Independent reported.

She is said to have secured a £50,000 loan for him to start a business without declaring her interest to authorities. She is also alleged to have demanded a £5,000 kickback for herself.

A source told the newspaper Robinson had harassed McCambley by constantly contacting him. McCambley, who had a girlfriend at the time, is said to have told her he had testicular cancer and could no longer sexually perform.

When they split up, she allegedly demanded the money back in the form of two cheques for £20,000 each, one to herself and one to her local church, where her sister is a pastor. It is not clear what happened to the other £10,000.

McCambley told a BBC Spotlight programme last Thursday that he had known Robinson since he was nine years old. He added that she was a regular visitor to his father William’s shop.

Robinson is also alleged to have had an affair with McCambley senior, along with two unnamed Democratic Unionist Party politicians.

She has not been seen since before Christmas. She has been expelled from her party and is thought to be receiving psychiatric treatment in a Belfast hospital.

Her husband Peter Robinson, who has denied claims he knew about the loan to McCambley, stepped aside from his position as Northern Ireland’s first minister yesterday for a six-week period.