A man was mistakenly arrested at Glasgow Airport over suspicions he was a French fugitive accused of killing his wife and four children, police have said.
A French police spokesman said that French and Scottish investigators have determined the fingerprints of the man detained yesterday do not match those of missing suspect Xavier Dupont de Ligonnes.
Mr Dupont de Ligonnes was subject to an international arrest warrant for the 2011 killings in a mystery that has transfixed France.
A businessman was stopped at the airport yesterday after arriving on a flight from Paris, according to two French sources close to the investigation.
Mr Dupont de Ligonnes, 58, is suspected of shooting his family dead - Agnes Dupont de Ligonnes, 49, along with Arthur, 21; Thomas, 18; Anne, 16; and Benoit, 13.
They were then buried under the terrace of their townhouse in the western city of Nantes.
Their bodies were found three weeks after the killings, during which time Mr Dupont de Ligonnes reportedly told his teenage children's school he had been transferred to a job in Australia.
He is said to have told friends he was a US secret agent who was being taken into a witness protection programme.
French prosecutors have said he killed all five of his victims in a "methodical execution", shooting them each twice in the head at close range with a weapon fitted with a silencer.
He is believed to have covered them in quicklime and wrapped them in sheets before burying them under concrete.
Yesterday, officers had picked out a suspect at the French capital's Charles de Gaulle airport, but there was not enough time to seize him, so they alerted British police, who confirmed an arrest had been made.
French newspaper Liberation reported that Mr Dupont de Ligonnes had undergone plastic surgery to change his appearance, citing police sources.
For years France has been gripped by the question of how Mr Dupont de Ligonnes had disappeared without trace, with some suggesting he may have killed himself. Hundreds of reported sightings only added to the mystery.
In 2015, a letter and photo of two of his sons, signed with his name and the message "I am still alive", was delivered to an AFP journalist but experts could not verify its authenticity.
The alleged killer evaded a police dragnet in the Var region of southern France in January last year after witnesses reported seeing a man resembling him near a monastery.
Additional Reporting PA
