For years Lord Lucan had been making his ex-wife Veronica's life a living hell. Almost as soon as the couple separated in early 1973 he began his campaign to gain sole custody of their three children.
Ever since the birth of their eldest child, Lady Frances, Veronica had been battling chronic post-natal depression and had been prescribed medication.
Her husband's gambling issues, and the financial strain these placed on the relationship, meant that after a particularly difficult Christmas in 1972, Lord Lucan moved out of the family home in Belgravia and into his own flat nearby.
Initially, Veronica wanted to make the floundering marriage work but all Lucan cared about was removing the children. Lady Frances, Lord George and Lady Camilla, from his wife's care.
He went to extreme lengths to try to prove she was an unfit mother, even resorting to parking his car outside the family home and spying on them.
Lord Lucan has not been seen for close to 50 years, with rumours having long swirled around whether he was still alive or in hiding. Even when he was declared dead in 2016 many believed he was still at large and evading justice.
Now, an expert has told the Mirror that photographs of a frail pensioner living in Australia are an exact match for Lord Lucan.
Professor Hassan Ugail - who successfully identified the Russian men behind the Salisbury Skripal poisoning - said: “I analysed these seven photos and they produced a match. This isn’t an opinion, it's science and mathematical fact.”
“These are the facts - you can’t cheat the algorithm.”
The revelation comes as it has also been revealed that in recent years the British pensioner identified as Lord Lucan has moved from house to house in Australia.
At the time of Lucan's campaign against his wife, employed private detectives to keep watch on his family and tried to persuade doctors to agree with him that his wife had "gone mad" - instead they all assured him she was suffering from depression.
He began to spread rumours about Veronica among his friends, claiming no one wanted to work for her.
The constant threats were taking their toll on Lucan's wife, who is even reported to have told one nanny that he had once hit her with a cane and feared that he would kill her one day.
But it was after a court case that saw the children returned to their mother's care that Lucan really stepped up his campaign again Veronica.
He dragged their closest friends and even Veronica's sister, Christina, into his plot and stepped up the constant watching of his wife, including taping many of their phone conversations.
Lucan also began to withhold money from Veronica in his bid to prove she was incapable of looking after their three children.
He is thought to have cancelled the regular food order she had, and he paid for, with Harrods, stopped payments to the milkman and even withdrew payments to the childcare agency she used to provide a live-in nanny, one of the conditions of her having custody of the children.
Determined to succeed on her own,Veronica resorted to taking a part-time job at a local hospital to ensure all the bills were paid on time.
But it didn't stop her estranged husband, who then resorted to plying one of the temporary nannies with drink so he could gain information.
Other nannies claimed there were regular phone calls to the house, with a man breathing heavily on the other end of the receiver and which could have been Lucan.
But then, suddenly, in October 1974, his mood seemed to life. His obsession with regaining custody of his children diminished and he changed the subject whenever his family problems came up.
That was until November 7, when he broke with routine - on the day Sandra Rivett was murdered.
Lucan had called his solicitor in the morning and arranged to meeting him at 3pm at The Clermont, where he was a regular - but he failed to show up.
He also failed to meet friends for lunch, also at The Clermont.
After meeting friend and literary agent, Michael Hicks-Beach, at his flat at around 6:30pm he drove him home at about 8pm but not in his usual car.
Lucan favoured a glamorous Mercedes but he was driving was has been described as an "old, dark and scruffy Ford" he had borrowed from another friend a few weeks previously.
After he had dropped Michael home he called The Clermont to check on a dinner reservation for later than evening but when the 11pm appointment arrived, he didn't show up.
It was at this time that the brutal events in Belgravia were unfolding.
It was a Thursday evening, which was usually Sandra Rivett's night off when she would see her boyfriend. However, that week she had changed it and had been out with him the night before.
After chatting to her boyfriend on the phone at about 8pm, Sandra set about putting the two younger children to bed before asking Veronica if she would like a cup of tea and going downstairs to make one.
Once she got into the basement kitchen she was immediately attacked by a man wielding a piece of bandaged led pipe. After making sure she was dead, her killer stuffed her body into a canvas mail bag.
Unaware of the horror downstairs, Veronica made her way into the kitchen to find out what had happened to Sandra. She shouted down and when she called for the nanny, she was also brutally attacked.
Desperate, she began screaming for her life and then says she heard the chilling sound of her own husband telling her to shut up.
Refusing to give up, Veronica bit Lucan's fingers when he hurled her onto the floor and then grabbed him between his legs, demanding to know where Sandra was.
He finally admitted to killing her and his terrified wife told him that she would help him escape if he would allow her injuries to heal for a few days.
Calmly, Lucan then walked upstairs to send his daughter to bed before going into one of the bedrooms. When Veronica followed him he, with horrifying calmness, told her to put a towel down on the bed so she didn't bleed on it and went into the bathroom to get a towel.
It was then Veronica saw her chance, knowing Lucan wouldn't be able to hear her, and fled for her life.
She raced to the nearest pub, The Plumbers Arms, and managed to scream what had happened before she fainted.
What Lucan did next is unclear but it is thought he headed to the nearby home of one of his eldest daughter's schoolfriends to see her mother, Madelaine Florman.
Madelaine was at home alone so ignored the persistent knocking on the door. A short time later she received a phone call but couldn't make out what was being said. When police examined the scene, they found blood on the doorstep belonging to two people.
At about 10:30pm, Lucan made a phone call to his mother and asked her to collect his children from the home they shared with Veronica, telling her there had been a "terrible catastrophe". He claimed he had seen Veronica fighting with a man in the basement and when he'd gone in to help, his wife had started screaming.
The last confirmed sighting of Lord Lucan was at the home of his friends, the Maxwell-Scotts, more than 40 miles away in east Sussex, where he had met with Susan Maxwell-Scott.
Lucan's final phone call was to his mother at 12:30am the following morning, telling her he would be in touch soon but refusing to talk to the police.
Meanwhile, Veronica was rushed to St George's Hospital after police forced their way into the home and found the body of Sandra Rivett.
When she was interviewed by police, Veronica, who was heavily sedated, was able to tell officers exactly what had happened and who had attacked her.
Despite thousands of rumoured sightings, Lucan has never been seen again.
