The 31-year-old male has not yet been identified, and was arrested on December 21. The Briton was last spotted walking into the mouth of the Channel Tunnel in Folkestone, Kent a week ago.
A French police source told the Daily Mirror they had caught the man after both British and French police teams were alerted to the incident.
They said: “They arrested him and took him out of the Tunnel at Coquelles.
“He was heading to France from England, and presenting a clear danger to all Tunnel users, including himself.
“He was running, so as to get to France as soon as possible.”
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Upon the man’s arrest, he was fast-tracked through the French court system and appeared in Boulogne-sur-Mer last Wednesday.
The police source added the man “refused to give his name and address” to the authorities.
They added: “Thanks to the British, he was soon identified as a thirty-one-year-old escaped prisoner.”
He was remanded in custody in France, ahead of another hearing on February 1 in the new year.
The man’s walk down the Channel Tunnel caused severe disruption to the Eurotunnel train service.
A spokesman said: “A person was detected inside the Channel Tunnel and taken into custody by the French Authorities.
“As there is now a criminal procedure in place we are unable to comment further at this time.”
The Mirror estimated the disruption to traffic caused by the incident cost Eurotunnel around £45,000 in revenue.
It is the third known incident of its kind, and happened in spite of massive security measures for the undersea tunnel.
In 2015, a Sudanese migrant walked the entire length of the Channel Tunnel from France to the UK.
Abdul Haroun was initially charged with obstructing a railway under the obscure 19th-century legislation Malicious Damages Act 1861.
He was sentenced to nine months in prison in June 2016, but walked free due to time served in custody awaiting the trial and was eventually granted asylum.
Two Iranians were sentenced to 14-months in prison in April 2016 after they completed the 31-mile walk from Calais to Folkestone in 2015.
The Channel Tunnel is operated by Getlink, who also run a railway shuttle between Folkestone and Calais.
Trains can travel up to 100mph along the Channel Tunnel line, posing huge danger to anyone walking the length of it.