The son of the woman thought to have been murdered by Lord Lucan has said the peer “could still be alive” following his mysterious disappearance 50 years ago.

Neil Berriman, who was given up for adoption as a baby, has been consumed by the case since he discovered he was the son of Lord Lucan’s children’s nanny Sandra Rivett more than a decade ago at the age of 40.

Ms Rivett’s body was discovered in November 1974 in the basement of 46 Lower Belgrave Street in central London but police found the prime suspect, the seventh Earl of Lucan, had vanished.

In a new three-part BBC Two series, Hampshire builder Mr Berriman receives the support of a former BBC investigative journalist Glen Campbell to map out what seems to be Lord Lucan’s likely escape from his homeland to a life of exile in Africa.

Lord Lucan
Lord Lucan vanished in November 1974 (PA)

According to Mr Campbell: “Throughout the late 1990s the Metropolitan Police were in possession of credible intelligence Lucan was still alive and hiding in Africa.”

No body has been found in the search for Lord Lucan, despite a decades-long manhunt.

Speaking about how he felt when he discovered he was Ms Rivett’s son, Mr Berriman said: “When it was confirmed Sandra was my birth mother, I fell into complete shock and could not believe somebody would do this to her. I was cross, angry and wanted that man caught.

“The emotional side of it all was incredibly sad and painful and I felt so sorry for her. Can you imagine what she went though? Total hell.”

He added: “She’s the mother I never knew, but that makes no difference.

Lucan
Sandra Rivett (BBC/Five Mile Films/Mirrorpix/PA)

“Sandra is still my mum and I will do the best I can for her. There is also no actual proof that Lucan was dead so he could still be alive.”

Discussing what has motivated his search, he added: “I was not going to give up on my mum, Sandra drove me as much as I drove myself, this was one puzzle I was going to finish.

“Nobody gets away with murder. It was all about Sandra.”

Lord Lucan was officially declared dead by the High Court in 1999, but there have been reported sightings in Australia, Ireland, Africa and New Zealand, and even claims that he fled to India and lived life as a hippy called “Jungle Barry”.

On the night of the peer’s disappearance, the nanny’s attacker also turned on Lady Lucan, beating her severely before she managed to escape and raise the alarm at a nearby pub, the Plumbers Arms.

The Plumbers Arms
The Plumbers Arms in Lower Belgrave Street, London, where Lady Lucan ran to after being severely beaten at her home nearby, the same night Lord Lucan vanished and the family nanny was found dead (Nick Ansell/PA)

Lord Lucan’s car was found abandoned and soaked in blood in Newhaven, East Sussex, and an inquest jury declared him the killer a year later.

In 2016, Lord Lucan’s son Lord George Bingham inherited his title as the eighth earl after he applied for a death certificate 42 years after his father vanished, under the Presumption of Death Act, which came into effect in 2014.

Mr Berriman corresponded with Lord Lucan’s wife Veronica, prior to her death in 2017, and met police officers for the new BBC series.

Also on the programme, Mr Campbell interviews Lord Lucan’s expatriate brother, Hugh, who points them onto a trail that leads to Eastern religion, Buddhist retreats and ultimately the east and west coasts of Australia

Lucan is set to air on Wednesday November 6 on BBC Two at 9pm. All episodes will be available on BBC iPlayer.