Holidaymakers are being offered Madeleine McCann tours of the holiday complex where she disappeared.
Tourists taking up the trips – which Madeleine's parents are said to find distressing – are invited to speculate on what happened to the then-three-year-old in May 1997.
The tours take visitors to the Praia da Luz apartment where the Rothley family were staying and the tapas restaurant where her parents Gerry and Kate were dining when she vanished. The organiser also takes his clients to nearby wasteland which police dug up in searches for evidence.
The tours are being offered on the internet by a British grandfather in his 60s who has become obsessed with the case since emigrating to Portugal.
Read more: Missing Madeleine McCann's twin brother and sister told 'everything' about her disappearance
A source told the Daily Mirror: "The guide is obsessed with Maddie.
"He's written thousands of words about the case and pored over maps, photographs and police transcripts."
The organiser started offering the tours in January and had the first visitor on March 8.
According to the blog used to advertise the tours, he is currently planning the fourth.
He aims the tours at Britons looking for a day trip but said he does not want payment.
In the first blog, the host said: "I think of this as the Luz Challenge. Our version of Mission Impossible.
"You have to come up with a way in which the McCanns, for whatever reason, disposed of Madeleine's body, and the body was not found in searches."
The McCanns have been cleared by police of any involvement in the disappearance of their daughter.
The guide says the tour starts at Apartment 5A at the Ocean Club Hotel, where the McCanns stayed.
From there they go a few hundred yards to the tapas restaurant – now closed – where her parents were eating, the spot where the McCanns' friend Jane Tanner saw a mystery man carrying a child. This was later ruled out as a sighting.
They will also take in the scene of the sighting by a retired businessman, who said he saw a man carrying a child in the direction of the beach.
Other places on the tour are the areas where police carried out searches two years ago and Our Lady of the Light church.
Police searched there and a nearby cemetery.
The man is said to have moved to the resort with his wife several years ago.