The sperm donor who believes he might be the father of OctoMom's brood says he donated his seed -- because Nadya told him she had cancer and had to act quickly.


Denis Beaudoin, who was in a three-year relationship with Nadya Suleman, told GMA he decided to help because she said she had ovarian cancer and time was a factor. He also claims he was not aware that Nadya was "doing any IVF at the time."

He doesn't know for sure if he's the dad, but wants a DNA test done. Suleman denies Beaudoin is the father.