Carlos the Jackal has written from his French jail to the US president, Barack Obama, asking him for help in locating his "former comrade-in-arms" Bruno Breguet.

The notorious criminal mastermind of a series of leftist terrorist attacks across Europe wants Obama to provide firm news of his whereabouts or, if dead, return his remains to his family.

Breguet, a convicted Swiss terrorist, was allegedly snatched by CIA agents backed by Nato naval commandos from a ferry between Italy and Greece in 1995. He has not been heard of since. There have been persistent rumours that Breguet died during interrogation at a secret CIA facility in Hungary at the end of 1995. Hungary has strenuously denied having had any secret CIA jails on its territory or later links to America's extraordinary rendition flights of terrorist suspects.

The Jackal - Venezuelan-born Ilich Ramirez Sanchez - kidnapped, murdered, robbed and bombed his way across the Continent in the 1970s and 1980s, and Breguet was his right hand man. He enjoyed the secret support of the Soviet KGB and used Eastern Europe, with the help of the communist secret services, as his armoury, supply base and R&R facility. Captured in 1994, he is now serving life for the murder of two French agents and an informer, and for a series of deadly bomb attacks in Paris and on French trains.

In the 1980s, Breguet was helping Carlos run a multinational group of ideological gun-slingers who enjoyed the secret backing of the KGB and the violent Palestinian resistance group the Popular Front for the Liberation of Palestine (PFLP) At the beginning of 1982, Breguet was caught with explosives in Paris and jailed by the French authorities. In March that year, Carlos wrote a menacing letter to the French government threatening terrorist attacks unless his lieutenant was immediately released. As there was no reply, the Jackal launched eight deadly attacks on French targets killing a total of 20 people and injuring many more.

After his early release from his French jail in 1985, Breguet lived untroubled in Austria, Germany and Switzerland, but mainly at his partner's house in Greece. In November 1995 he sailed to Italy for a family visit in Switzerland.

His mysterious disappearance greatly exercised Carlos and, 14 years later, the release of America's terrorist suspect prisoners from Guantanamo Bay on Obama's orders appears to have prompted Carlos to write to the new president of the United States. Though a seasoned terrorist gunman and serial killer, the Jackal appears to show a touching faith in Barack Obama representing a new beginning for America and a closure for old cold-war events.

Unsurprisingly, the French authorities have refused to comment on the letter, but Breguet's brother, Ernesto, confirmed it in an interview in Ticino, the Breguet brothers' Swiss home canton.

The Ticino regional daily La Regione quoted Ernesto Breguet as saying: "When Carlos believes that he must write a letter to Obama then clearly he must do so."

Details of the letter are telling: "Mr President, Heartfelt congratulations on your decision to close America's CIA jails. Our comrade-in-arms Bruno Breguet, a Swiss citizen, was kidnapped from a ferry plying between Italy and Greece. It was a special operation supported by Nato naval forces on November 11, 1995. Since that date Bruno Breguet has disappeared without a trace."

In his letter Carlos gives further details about the puzzling events of that day. On reaching Italy on the Greek ferry, Breguet was refused entry by the Italian authorities and he boarded the ferry once again to sail back to Greece. However, he never arrived and Carlos in his letter points an accusing finger at "CIA agents backed by Nato naval commandos".

After appealing again for the release of Breguet, or at least information about his fate, Carlos ended his letter with the loaded phrase: "As your grandfather would have said it, Mr President, Allahu akhbar - God is great!"

The only firm official statement about Breguet's disappearance was made by the Greek interior minister in January 2006 - three months after the event - in response to Swiss inquiries. According to the venerable Swiss daily Neue Zurcher Zeitung, the Greek minister told the Swiss ambassador to Athens that "Greece has no information about Breguet's whereabouts" adding that, contrary to earlier reports, the man had not been arrested by the Greek authorities.

But, in a further twist to this extraordinary cloak and dagger tale, the newspaper noted that right after Bregeut's disappearance there were strong but unconfirmed reports that Carlos's former top henchman wanted to retire from the terrorist scene altogether and was murdered by his own comrades-in-arms for "his treachery". Comment on this story here