The 52-year-old singing sensation, who shot to fame after finishing second on 'Britain's Got Talent' in 2009, handed over the huge sum to Gerry, 59, after he visited her in the US and told her he would kill himself if she didn't give him the money, reported Daily Express.
"It was emotional blackmail. Susan felt like she had no choice and had to give the money to him. She doesn't deal with pressure very well and he knew the buttons to press," Susan's nephew Alan said.
But Susan's family are now concerned Gerry might ask the 'I Dreamed a Dream' hitmaker for more cash at a later date.
"In New York she hadn't spoken to him for weeks when he asked for the 50,000 pounds. She wasn't well and had a viral infection and tonsillitis. She just said she would give it to him," Susan's sister Bridie McCaw said.
A spokesman for the singer said: "It is true. There were threats of suicide if she did not pay yet another large amount of money.