Carlos trapped after secret deal between France and Sudan: Richard Dowden and Charles Richards trace the undercover ties which sealed the terrorist's fate

LINKS between the French secret service and Sudanese security chiefs have been developing for almost a year but the details which emerged yesterday pose as many questions as they answer.

Which state put Carlos on a plane to the sleepy confluence of the White and Blue Niles? Why, and why did it take so long to apprehend him? And who were the mysterious Arab nationals identified as Carlos' fellow travellers?

Reports emerged yesterday of favours and payments made by France to Sudan in exchange for handing over Ilich Ramirez Sanchez - Carlos - undermining denials by French and Sudanese officials that there had been any deal. Contacts between the two governments and their security services have been traced in recent months by diplomatic gossip and specialist journals such as Africa Confidential and the Indian Ocean Newsletter.

In February the latter reported that representatives of several Sudanese ministries, including Defence, and the secret service, had been in Paris many times in past months. 'In addition to the Sudanese generals who visited France's Defence Ministry at the beginning of December and the joint ministerial delegation which in mid- January was trying to get in touch with major industrial companies such as Total and GTM (Les Grands Travaux de Marseille), members of the Sudanese secret service met their French opposite numbers in the DGSE (Direction general de la securite exterieure) four times in as many months . . .', the Newsletter said on 29 January. It added: 'The exchange of intelligence on the situation in Sudan's frontier zones with the Central African Republic, Chad, Uganda and Zaire was at the centre of discussions between French and Sudanese military men.'

In February, Africa Confidential carried a simlar report, describing the rush of Sudanese intelligence officers to Paris as a 'flurry'. It suggested that Paris was using Khartoum to open a dialogue with the Algerian Front Islamique du Salut (Islamic Salvation Front) and to try to curb what the French see as destabilising Islamic tendencies throughout Africa. There is also a commercial aspect involved: Sudan Airlines has recently bought four Airbuses from France and the French oil company Total has a substantial concession in Sudan's undeveloped oil deposits.

Sudan - huge, potentially wealthy and strategically important in East and Central Africa - has become increasingly isolated by Western countries because of its brand of Islamic fundamentalism and accusations that it is harbouring terrorists. For these very reasons it has become a prime target of French influence. Paris offered Khartoum an end to isolation, a resumption of aid and arms, and perhaps a defender on the top table, while for Paris Khartoum offered an extension of French influence in a traditionally Anglophone area, lucrative commercial prospects - and Carlos.

Yesterday, sources in Paris confirmed that el-Fatih Irwa, an East German-trained Sudanese security chief, visited Paris several times this year and is a friend of Colonel Jean Claude Mantion, who was the French 'pro-consul' in the Central African Republic until last year but since appears to have been a personal emissary of Charles Pasqua, the French Interior Minister. Yesterday, the French daily, Liberation, said that Sudanese security chiefs had been in Paris to visit the DGSE, and quoted French officials as saying that satellite pictures of rebel positions in southern Sudan had been given to the Sudan security chiefs by French intelligence officers who had also arranged for Sudanese troops fighting rebels of the Sudan Peoples' Liberation Army to cross the Central African Republic and Zaire in pursuit of the rebels.

A Sudanese government spokesman in London, however, quoted Mr Pasqua as saying that Sudan had asked for nothing in exchange for the extradition. He added that relations between Sudan and France were excellent; a French- Sudanese commercial and economic co-operation council would soon be set up.

As to where Carlos had come from when he arrived in Khartoum, the French and Sudanese authorities say they cannot reveal such details at present. They only say he was travelling on a forged Arab diplomatic passport. Rumours abound. All the usual suspects are cited: Syria, Libya, Iraq, Iran. And in the murky world of intelligence, information and disinformation are liberally mixed.

Carlos' last known refuge was Syria, which for long has played host to a rogues' gallery of international ne'er-do-wells, including the Palestinians Ahmed Jibril and Fathi Shkaki. Syria not only provided a base for groups using political violence: it was itself accused by Britain of being behind the attempt in 1986 to blow up an Israeli jet flying out of Heathrow.

Syria would have had a motive in divesting itself of an embarrassment such as Carlos at little political cost. The French and Sudanese authorities agreed to declare that Carlos arrived six months ago or in December, depending on the account. Either date would have coincided with Syria's efforts to show it was not a state sponsor of terrorism, as part of its public relations campaign to prepare for the summit meeting in Geneva in February between Presidents Bill Clinton and Hafez al-Assad.

Syria would not have been able to claim credit for helping the fight against international terrorism without admitting it had harboured Carlos all along. It could, however, have tipped off the French, and told the Americans in full candour that Carlos was no longer lingering in Damascus.

Other countries in the region with a history of backing radical groups, including Iraq, Libya, and Iran, have less interest in currying favour with the international community. Indeed, Libya is still believed to be home to the most notorious assassin of all, Sabri al- Banna, known as Abu Nidal, whose targets have been Palestinian moderates and Britons. And Libya has still not handed over two intelligence agents wanted in connection with the blowing up of Pan Am Flight 103 over Lockerbie.

Carlos did not travel alone. His partner, Magdalena Kopp, left him some time ago and now lives in Venezuela, according to her mother. The international network of which Carlos was the hub was never disbanded, although his Palestinian mentor, Wadi Haddad, died in 1978.