(London, UK)- Souleymane Guengueng had good reason to celebrate yesterday. His long march in search of justice from the Chadian dictator he accuses of torture could soon be over.

Mr Guengueng, 53, wears thick glasses after almost losing his eyesight in jail, where he says he was subjected to total darkness followed by periods of powerful light. The former civil servant told The Independent in an interview two years ago: 'I did not know if it was night or day. There were eight of us in the cell built for a single person: my skin peeled off in the stifling heat.'

He said yesterday after Mr Habré's indictment by Belgium for crimes against humanity and torture: 'I can already see Hissène Habré sitting in a Belgian jail.'

Nobody knows the exact number of victims, although the Chadian Truth Commission in 1992 accused Habré's government of 40,000 political murders and systematic torture.

His regime was marked by widespread atrocities, including periodic campaigns of violence against ethnic groups whose leaders he perceived as rivals.

As in the UN war crimes case against the former Yugoslav leader Slobodan Milosevic, the difficulty for the Belgian prosecution will be to produce the 'smoking gun' that proves the direct link between Mr Habré and the atrocities.

But Mr Guengueng, who has persuaded almost 800 relatives of victims and survivors of Mr Habré's alleged atrocities to pursue their cases through the courts, is confident. 'It was Habré who set up the political police. He was kept informed of everything.'

The prosecution case will be bolstered by a treasure trove of documents discovered in May 2001 by Human Rights Watch in the abandoned offices of the DDS. According to the human rights organisation, they detail how Mr Habré placed the DDS under his direct control, organised ethnic cleansing, and kept tight control over DDS operations. But there are also witness statements. In February and March 2002, the Belgian investigating magistrate Daniel Fransen visited Chad together with a Belgian state prosecutor and four policemen, to interview victims, witnesses and even some of Mr Habré's alleged collaborators. They also visited mass grave sites.