Sir Paul McCartney has found himself at the centre of a paternity investigation over claims he faked a DNA test more than 20 years ago. Bettina Hubers, 46, claims the former Beatle is her biological father following an affair with her mother Erica while the band were playing in Hamburg, Germany in the early 1960s. The music legend has denied paternity, claiming to have taken a DNA test proving so in 1983. But Hubers is now accusing MCCartney of "faking" the test by sending a body double to give a blood sample. She says, "The signature on the documents he signed at the time was false. We found that the signature is from a right-handed person and he is not. "I want a new paternity test. It is my right. It has taken so long because we have been fighting to find out the truth." A spokesman for the public prosecutor's office in Berlin confirmed they are investigating a paternity case involving MCCartney. If prosecutors find there is a case to answer, the singer could be arrested for fraud the next time he visits Germany.