The son of the nanny allegedly murdered by Lord Lucan is convinced he has found him in Australia, a claim that the missing man’s son regards as “very unlikely”.

Neil Berriman, 52, believes that John Bingham, 7th Earl of Lucan, is living in a shared suburban house. He discovered ten years ago that his mother was Sandra Rivett, the nanny beaten to death in the peer’s London home in 1974. Lord Lucan disappeared, aged 39, and was declared legally dead in 1999.

Mr Berriman has spent the past decade trying to trace him and previously believed that he had been living in Africa until as recently as 2002.

Left, Neil Berriman, the son of Lord Lucan’s murdered nanny; right, George Bingham, son of the infamous British aristocrat.

He has presented evidence to Scotland Yard’s cold case unit. “I met a lady officer, who took details from me about my investigation work that I’ve been doing for the last ten years, and I believe that I’ve found the man that could be Lord Lucan,” he told the Daily Mirror. He said that his allegations were taken seriously. The man is in his mid-eighties and living as a Buddhist in a shared detached house. Mr Berriman, who lives in Milland, West Sussex, declined to name the city.

“There is no doubt in my mind he escaped that night, with the help of friends who helped him get across the Channel and get a new passport, and incredibly he is still alive,” he added.

George Bingham, 8th Earl of Lucan, 52, said he believed that his father was long dead. “After so many sightings over so many years, one can’t help but express some scepticism,” he told The Times. “This does seem very unlikely.” He was more excited by an addition to his family. “I have a newborn chum, Charles, who came on December 30.”

Scotland Yard said that the case remained open.