Broadbent, 71, said he had been apprehensive about travelling to Venice because of the risks caused by the Covid-19 crisis.
Bunton was charged with stealing a portrait of the Duke of Wellington by the great Spanish painter Francisco Goya from the National Gallery in 1961.
The story of an ex-bus driver and cabbie from Newcastle upon Tyne who was accused of executing one of the most infamous heists in British history has been given a starring role at this year’s Venice film festival.
Eventually, Bunton sent an anonymous letter to the paper with a left-luggage ticket for Birmingham’s New Street railway station, where the portrait was found in a locker.