Cornwell, an American best known for her Kay Scarpetta books about a pathologist, bought the Sickert works, a mix of paintings, drawings and prints, for about £3m while researching her book Portrait of a Killer, published in 2002.

The controversial book concluded Sickert was Jack the Ripper, who murdered prostitutes in London’s East End at the end of the 19th century.

Cornwell was drawn to the idea that Sickert, noted for his scenes of London life, might have been the Ripper because he painted macabre scenes and was interested in the murders.

She bought the Sickerts largely to try to prove that he was the murderer. Cornwell used DNA testing on the paintings to compare it with DNA on what were, allegedly, letters from the Ripper, but to no avail.

The promised donation to Harvard’s Fogg Art museum near Boston is a result of the help that the gallery gave to Cornwell in her research, according to September’s edition of The Art Newspaper. Experts gave her use of forensic equipment to investigate the drawings, paintings and letters.

Among the paintings Cornwell is giving is Putana a Casa, a picture of a prostitute, that she said “resembled mortuary photographs of (Ripper victim) Catherine Eddowes and is suggestive of the mutilation to the right side of her face”.

The Harvard donation includes the guest book from the Lizard hotel, Cornwall, which Cornwell believes contains drawings by Sickert in the same hand as sketches in letters allegedly written by the Ripper.

During her research it was said that Cornwell destroyed a Sickert canvas, which she has denied. One painting she bought and had tested, Broadstairs, has not been donated.

Last year Cornwell took out a newspaper advertisement to deny accusations that her Sickert theory was an obsession.

More than 170 names have been put forward as the Ripper, including the Duke of Clarence, Montague John Druitt, a barrister who killed himself just after the last murder, and Michael Ostrog, a Russian thief.

Asked why she was donating the Sickerts, Cornwell said: “I wanted it to be a gallery where scientific examination of the Sickerts can continue.”

Explore UK News

• Science News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• Savers left in limbo as Icesave freezes deposits
• Kennel Club changes breeding rules
• Passengers triple risk of fatal crashes