A postcard allegedly sent by a murdered woman shortly after she disappeared more than 20 years ago is a fake, according to police in England.
Sally Ann John, then aged 23, went missing while working as a prostitute in the red light district in Swindon, England, in September 1995.
Wiltshire Police said analysis of the postcard has led detectives to conclude it was not written by Miss John but its true author remains unknown.
Police disclosed the existence of the postcard, sent shortly after Miss John disappeared, on BBC1's Crimewatch this week.
The postcard, which is marked "2 Oct 1995", was sent to someone known only as "Clive" and purports to be from Miss John, who says she is living in London.
It says: "Dear Clive,
"Thought I'd write as I heard you've been missing me and that you were rather worried that something had happened to me. As you can see I'm in London now. But no one compares to you Big Boy.
"Love Sally xxxxxx"
A forensic expert told the programme an analysis of Miss John's handwriting had proven the postcard was a fake.
Miss John's mother Lesley told the programme: "I thought something must have happened to her because she left all her things, everything she owned in the flat she lived in. She didn't take anything with her.
"It's a horrible feeling that your daughter may have been murdered or has been murdered because you can't do anything about it, you can't do anything.
"I just want her found, I really do want her found and whoever did this to be counted for. I would like to know where she is, so we can put her to rest and this whole nightmare will be over."
The night Miss John disappeared she had been working on the streets between the bus station and train station in central Swindon. She was last seen at around 10.50pm on Alexandra Street.
Her disappearance was initially treated as a missing person's inquiry but police launched a murder investigation in 2014. Her body has never been found.
The following year Wiltshire Police began forensically searching her former home, a flat in Kimmeridge Close in Nythe, Swindon. Three men were arrested on suspicion of kidnap and murder and later bailed.
Wiltshire Police is offering a reward of £25,000 for information which leads to the discovery of Miss John's body or brings those responsible to justice.
Detective Sergeant Don Pocock said: "It has been nearly 22 years since Sally disappeared, I appreciate this is a long time and no doubt friendships, relationships and lives will have changed dramatically since then.
"But if you have any information about what happened to Sally, it could be the missing piece in our jigsaw.
"Sally's family are understandably desperate to know what happened to their daughter and we are doing all that we can to ensure they have some kind of closure.
"We are offering up to £25,000 cash reward to anyone who can provide us with information which will lead to the discovery of Sally's remains, or anyone who can provide us with information which secures a conviction at court in relation to those responsible for her murder."
Police are keeping an open mind as to whether Christopher Halliwell, who is serving life imprisonment for murdering two young women from Swindon, could have killed Miss John.
During the Crimewatch show Mr Pocock was asked whether Halliwell was "still a line of inquiry".
"We remain open minded in relation to our lines of inquiry and we have liaised with our colleagues that are dealing with Mr Halliwell," he said.
Halliwell's job as a taxi driver gave him the ability to cruise the streets late at night without suspicion.
Both Sian O'Callaghan and Becky Godden were murdered after leaving nightclubs in Swindon and getting into taxis.
The father-of-three initially wrongly believed Miss O'Callaghan, 22, was a sex worker, while Miss Godden, 20, was a prostitute.