London, Mar 09 : Troubled singer Amy Winehouse's father Mitch has threatened to sue to her estranged husband Blake Fielder Civil's mother Georgette for waging an 18-month hate campaign against him.

Although the estranged couple are materializing their divorce, Blake's mother has lashed out at Winehouse for her alleged affairs and her father''s controlling ways.

Winehouse''s father Mitch has also alleged that Georgette has been harassing him by sending him menacing text messages and threatening to stab him.

"She was screaming, ''If I had a knife I''d stab you'', it was terrifying. She''s like a stalker trying to make our lives hell. She''s blaming my daughter for her son''s failings and she''s out to destroy Amy," the Daily Star quoted Mitch as saying.

Mitch also claimed that he immediately informed the police after receiving a threatening letter from Georgette.

Meanwhile, British tabloid The People has confirmed that after receiving complaint from Mitch, the police gave Georgette Civil an official warning. (ANI)