Convicted French trader arrested at border after odyssey to pope, appeal to president

Former trader Jerome Kerviel, closes his eyes during at a press conference in front of his hotel, in Ventimiglia, Italy, near the French border, Sunday, May 18, 2014. The rogue trader facing three years in prison for one of the biggest trading frauds in history is appealing to the French president for mercy. Jerome Kerviel, who almost took down his bank, Societe Generale, with 4.9 billion euros in losses, has been on a months-long pilgrimage back to France after meeting the pope. He stopped his return just short of the border Saturday. Kerviel, convicted in 2010, insists he was the victim of a system that allowed his illegal trades as long as they made money. An appeals court threw out a fine equal to his losses, but upheld his prison sentence. Kerviel is supposed to report to start his sentence by Sunday or be considered a fugitive. (AP Photo/Claude Paris) (The Associated Press)

Former trader Jerome Kerviel, center, surrounded by his lawyer David Koubbi, right, and priest Patrice Bourrier, speaks during a press conference in front of his hotel, in Ventimiglia, Italy, near the French border, Sunday, May 18, 2014. The rogue trader facing three years in prison for one of the biggest trading frauds in history is appealing to the French president for mercy. Jerome Kerviel, who almost took down his bank, Societe Generale, with 4.9 billion euros in losses, has been on a months-long pilgrimage back to France after meeting the pope. He stopped his return just short of the border Saturday. Kerviel, convicted in 2010, insists he was the victim of a system that allowed his illegal trades as long as they made money. An appeals court threw out a fine equal to his losses, but upheld his prison sentence. Kerviel is supposed to report to start his sentence by Sunday or be considered a fugitive. (AP Photo/Claude Paris) (The Associated Press)

Former trader Jerome Kerviel, attends a press conference in front of his hotel, in Ventimiglia, Italy, near the French border, Sunday, May 18, 2014. The rogue trader facing three years in prison for one of the biggest trading frauds in history is appealing to the French president for mercy. Jerome Kerviel, who almost took down his bank, Societe Generale, with 4.9 billion euros in losses, has been on a months-long pilgrimage back to France after meeting the pope. He stopped his return just short of the border Saturday. Kerviel, convicted in 2010, insists he was the victim of a system that allowed his illegal trades as long as they made money. An appeals court threw out a fine equal to his losses, but upheld his prison sentence. Kerviel is supposed to report to start his sentence by Sunday or be considered a fugitive. (AP Photo/Claude Paris) (The Associated Press)

A Frenchman convicted of one of history's biggest trading frauds has returned home to serve prison time after a pilgrimage to the pope and a plea for presidential clemency.

Jerome Kerviel, in footage shown on French television, crossed the border from Italy to France by foot late Sunday night. A police official in the French border town of Menton said Kerviel was in custody just after a midnight deadline to begin serving his sentence.

Kerviel was sentenced to three years in prison in a 2010 verdict that was upheld recently by France's highest court.

Kerviel cost his bank Societe Generale 4.9 billion euros in losses in 2008. He says the bank quietly welcomed his unauthorized trades when they earned money but later turned against him.