"Ms Nicholas says this approach was misguided as the private and professional lives of freelance art dealers such as the Hunts could not be separated. She reserves her harshest criticism for the Wiesenthal Centre. The "sensational and calculated manner" in which Dr Samuels first announced his suspicions in an open letter at a time when Ireland held the EU presidency was "both undiplomatic and offensive".

"The decision to challenge the Irish authorities in a sort of blackmail game was unprofessional in the extreme."

Her report examines a 30-page wartime intelligence file held in the Irish Military Archive, which she says is the basis for the allegations of trading with Nazi dealers; the existence of this file was publicly revealed only last year.

Documents on the file show that gardaí kept careful track on Ms Hunt, who was German-born, during the war and advised against her working at Foynes, which was a flying boat station.

However, Ms Nicholas says there is no evidence of