A French aristocrat suspected of murdering his wife and four children before disappearing without a trace was arrested in Glasgow, it was said.
Xavier Dupont de Ligonnès has not been seen since the April 2011 massacre.
He left in pursuit of the bodies of Agnès, 49, and the children Tomas, 21, Arthur, 18, Anne, 16, and Benoit, 13, were found buried in the garden of the family home in Nantes, in the west of France, with their two company labradors.
On Friday night, French media reported that De Ligonnès had been arrested at Glasgow Airport following a flight from Paris.
"He was traveling under a false identity and had completely changed appearance," said an investigative source.
"He did not attempt to resist an arrest, but the information provided matched what is on a Europol search card." The data is now verified and is now in the hands of the police. Scottish. "
Europol is the EU law enforcement cooperation agency that has been helping De Ligonnès hunt for eight years.
Last year, police searched underground caves and abandoned potassium mines in the Roquebrune-sur-Argens region of southern France, where De Ligonnès was spotted by a CCTV camera in April. 2011.
He had fled Nantes a few days earlier after his neighbors said they had not seen the family for more than three weeks.
The detectives who visited initially found a sliced leg under the garden terrace, then discovered the bodies of those who had been killed.
De Ligonnès is native of Versailles, home of kings and queens of the pre-revolutionary period of France. He was technically a count able to trace his lineage from generation to generation.
In confiscated e-mails, he declared himself to be part of a Roman Catholic elite superior to the "masses".
"I think I have a superiority complex, you can call it like that," he writes. "But it's based on a simple observation: I belong to a group of intelligent, determined, balanced people who are physically and morally healthy, and they are rare compared to the masses."
Recalling her strict and dedicated childhood, De Ligonnès added: "All my adolescence was devoted to religion and faith, under the influence of my grandmother and mother, so much so that I did not rebelled like other teenagers, or chasing girls. "
De Ligonnès was last seen on April 15, 2011, as he was leaving a budget hotel in Roquebrune-sur-Argens, abandoning his car there.
He was carrying a backpack as he walked through a parking lot to the surrounding countryside and was photographed by a camera.
Extensive searches were carried out in the region between April and June 2011 and, acting on new information, the police took them back last year without finding anything.
According to one theory, De Ligonnès could have committed suicide in the days following the massacre, in which case the police were looking for remains of his body.
However, prosecutors had never ruled out the possibility of De Ligonnès living in the street, or being hid by members of his extended family, who own country houses in France.
The ancestors of De Ligonnès, including the poet Lamartine of the nineteenth century, originally lived in a province in southern France called Rouergue.
Five months before the murders, De Ligonnès said that he had inherited the .22 rifle from his father and that he had started training to target in a shooting club in Nantes.
The receipts found in his home also reveal that he had bought a muffler, a shovel, a two-wheeled cart, lime, and other equipment that could have been used to bury the bodies.
It also appeared that De Ligonnès, who ran several Internet businesses, was experiencing serious financial difficulties. Among those to whom he asked for money was a mistress in Paris.