The estate of the former Beatle George Harrison filed a £5.5m law suit yesterday against a doctor who treated the late musician, accusing him of forcing the guitarist to sign autographs on his death bed.

The suit filed in Brooklyn Federal Court claimed that Dr Gilbert Lederman, director of radiation oncology at Staten Island University Hospital, a co-defendant, had coerced the dying man to autograph his son's guitar and sign autographs for his two daughters.

It also accused Dr Lederman of using Harrison's treatment to gain publicity for himself and the hospital against the wishes of the musician, who died of cancer on 29 November 2001, about two weeks after he had left Staten Island for California.

Harrison was treated for about three weeks in New York before his death. The suit claims Dr Lederman "preyed upon Mr Harrison while he was in a greatly deteriorated mental and physical condition by coercing" him to sign a guitar and other autographs for his son and daughters as he was being prepared to leave Dr Lederman's care.

The suit alleges that the musician tried to resist the request. "I do not even know if I know how to spell my name anymore," he said.

It alleges that Dr Lederman responded by saying: "Come on, you can do this," and held Harrison's hand as the musician wrote his name on the guitar "with great effort and much discomfort".

The doctor's lawyer, Wayne Roth, said: "As far as Mr Harrison being forced to sign the guitar goes, he absolutely and categorically denies that."

The suit says after Harrison's death, Dr Lederman gave a story about the guitar to the National Enquirer.