Michael Jackson was beaten so severely by his father, he was left sterile, it has been claimed.

The late 'Thriller' star reportedly told his physician Dr. Arnold Klein he didn't produce sperm because he was repeatedly kicked in the testicles by Joe Jackson when he was a child.

The doctor allegedly agreed to help the singer - a personal long-time friend - by donating his sperm so he could have a family.

Arnold's former lover Paul Gohranson told RadarOnline: "He told Dr. Klein that he thinks that's where the damage was done because he said his testicle was never the same again.

"He said it was enlarged and was always painful. So that's why he said Arnold donated his sperm because he didn't have the ability to even donate sperm, he wasn't producing it anymore."

Michael had three children, Prince Michael I, 12, Paris, 11, and seven-year-old Prince Michael II, who is also known as 'Blanket' and Paul is adamant that Arnold is the biological father of the eldest two.

Michael's ex-wife Debbie Rowe, who worked for Arnold, is the biological mother of the two kids.