On a sunny July afternoon in 1986 Suzy Lamplugh, the daughter of a solicitor and swimming instructor, vanished forever in one of the most notorious unsolved cases in recent criminal history.

The 25-year-old went missing after leaving the estate agency where she worked to meet a Mr Kipper at a house in Fulham, south-west London.

Her suspected abductor was a suave, dark-haired, man clutching champagne as he climbed out of his black BMW to view the house. She was seen with the man at 1pm and minutes later they were both seen walking away from the property. Following the meeting Lamplugh would never be seen again.

Her white Ford Fiesta was discovered on a nearby street with the doors unlocked, the handbrake off and the ignition keys missing. Her purse, still containing £15, was in the pocket of the driver’s door. Her disappearance was reported to the police at 6.45pm that day.

As the years passed the police received countless calls from people all over the world, from Saudi Arabia to Greece, claiming to have seen Lamplugh. Detectives also went to Belgium to interview a Mr Kipper but found he was not their man.

Detectives went on to interview suspects on two continents and in some of Britain’s most secure prisons, yet these yielded not one arrest.

The most promising lead was to come in April 1989. Three years after Lamplugh’s disappearance police conducted the first of three interviews with John Cannan, a convicted killer, whose prison nickname was Kipper.

Cannan, a former car salesman, was convicted in July 1988 of murder and sexual offences. His preferred targets were professional women.

He was given three life sentences with a recommendation never to be released for the murder of newlywed Shirley Banks, in Bristol, in October 1987, the attempted kidnapping of Julia Holman on the previous night, and the rape of a woman in Reading in 1986.

It was revealed that Cannan was released from a hostel only days before Lamplugh went missing and he resembled a photofit of a man seen with her on the day she disappeared. A former girlfriend said Cannan had “a strong interest” in the case and that Lamplugh may have been in a relationship with him. But Cannan denied any involvement, and investigations failed to produce any evidence linking him to Lamplugh’s disappearance.

Police would go on to question him twice more. In August 1991 Cannan wrote a letter to the local paper, Sutton News, denying any part in Lamplugh’s disappearance.

In November 2002 the Crown Prosecution Service decided there was insufficient evidence to charge Cannan. That same month Scotland Yard held a press conference at which, in a rare move, officers named him as the man they believed had murdered Lamplugh. They confirmed this again in 2006 when arguing against any reduction in his tariff.

Cannan subsequently complained via his solicitors about the police publicly naming him, saying he was “devastated and distressed”. He remains the prime suspect.

Lamplugh was officially declared dead in 1994. Her disappearance triggered a campaign by her mother, Diana, not only to establish her fate but also to try to safeguard others and to protect women from violence.

Diana launched the Suzy Lamplugh Trust just months after her daughter’s disappearance. Generations of freshers at universities were handed free rape alarms – known as Suzy Lamplugh alarms – and they campaigned for more street lights to protect women. Diana was awarded an OBE in 1992 for her work with the trust.

Both of Lamplugh’s parents died without ever finding out what had happened to their daughter. Diana died in 2011 after suffering from a stroke and alzheimer’s disease. Lamplugh’s father, Paul, who had Parkinson’s disease, and was awarded an OBE, died with his three surviving children by his side in June this year, having spent the rest of his life searching for his daughter.

Over the intervening years following Lamplugh’s disappearance officers examined thousands of lines of inquiry and carried out DNA tests on 800 unidentified bodies.

In August 1992 it was believed Lamplugh’s body had been found buried in the Mendip hills, in Somerset, but police ruled that out. In December 1994 claims by Michael Sams, who was serving a life sentence for murder and kidnap, that he killed Lamplugh, were dismissed by the family as a “sick hoax”.

In December 1999 Diana was told her daughter’s body could be at an abandoned army barracks in Norton, Worcestershire. A few months later, in May 2000, after further investigations, police announced they were reopening the case.

In 2008 police investigated possible links between the Lamplugh case and Steve Wright, a former QE2 steward, who was jailed for the murder of five female sex workers in Ipswich, Suffolk. Wright’s former wife, Diane Cole, revealed a link between him and Lamplugh, who had worked on the luxury QE2 liner as a beautician, but the investigation came to nothing.

In August 2010, they began a new search for Lamplugh’s body after a tipoff from a potential witness who said he saw a mound of soil at around the time she disappeared at Norton army barracks. Scotland Yard officers used ground-penetrating radar to examine the site, which had been previously searched in connection with the inquiry. But nothing was found.

Since her disappearance 32 years ago detectives have apologised for “significant opportunities” that were missed during the original inquiry; they said that if those chances had been grasped there might have been a prosecution years ago.

Paul Lamplugh last spoke publicly about his daughter in 2016, saying he would have to accept that she mighty have been killed deliberately and that he would probably never know who did it. He added: “I miss Suzy more now … I think the older I get the more I miss her.”