Maputo — Relatives of those charged with the murder of Mozambique's top investigative journalist, Carlos Cardoso, made two attempts - one successful and one unsuccessful - to bribe a key prosecution witness, Osvaldo Muianga ("Dudu") to change his story.

Muianga's mother, Fatima Razaco, told the court on Friday that the first bribe, in February 2002, resulted in Muianga retracting his original statement in which he had placed the brothers Ayob and Nini Abdul Satar, and former bank manager Vicente Ramaya, at conspiratorial meetings in the Rovuma hotel at which murder was planned.

Razaco said that Nini Satar, despite being a prisoner in a top security jail, was regularly in contact with her through mobile phones. In early 2002, he promised 200,000 dollars if Muianga would change his statement.

His sister Farida delivered post-dated cheques, totalling over a billion meticais (some 50,000 dollars) as "security".

Evidently this worked, for Muianga did indeed retract his statement, and claim that he had been induced to make it by Satar's enemies, notably by Gary Rouper, former managing director of the Polana Casino.

Razaco said she had believed Satar's claims of early 2002 that he had the judge and attorneys in his pocket, and so there was no point in Muianga resisting his offer. "So I obliged my son to sign the retraction", she said. "Later I realised it was all lies, and that there are no judges or attorneys on Nini's side". But once Muianga had retracted his statement, Satar reneged on the deal. He asked for the cheques back, promising Razaco that he would pay the bribe. She gave the cheques back, but Satar did not pay her anything. She did, however, have the good sense to keep photocopies of the cheques (although she told Satar she had not done so).

In October, Muianga changed his story again. Once again the relatives of the accused tried to use Razaco to manipulate her son. This time they wanted him to speak on behalf of the accused at the trial: a document was drawn up for him, in which he would claim that lawyer Albano Silva obliged him to incriminate Ramaya and the Satars.

Razaco claimed that Ramaya's wife, Mariamo, Ayob Satar's wife, Zumaia, and a second Satar sister, Rachida, were involved in this bribe attempt. They gave her 5,000 US dollars "as a sign of good will".

Mariamo promised her more cash, and even a house at the beach resort of Bilene, if she persuaded her son to copy out the document in his own handwriting. Razaco even claimed that one evening Ramaya's lawyer, Abdul Gani, telephoned her to urge her that her son should sign the document.

More money was forthcoming: via his sisters Nini Satar sent her another 1,500 dollars and over 100 million meticais, saying this was partly from him and partly from Mariamo. But Razaco never took the document to her son, and turned the money over to the police. Satar continued phoning her - but she taped the calls. She said she could not refuse to take the calls "because I'm afraid of them".

The defence lawyers, Gani in particular, objected to Razaco giving testimony. The bribes were the subject of a separate case, and for Razaco to speak about them at the murder trial would be a violation of sub judice rules. The president judge, Augusto Paulino, overruled these objections.

Gani, infuriated by the claim that he had rung up Razaco, interrupted her testimony to lodge "a solemn complaint". "She is saying things she cannot prove, she is denigrating people", he exclaimed. "We don't know who this person is, what her criminal record is. We too should be respected in this court".

Judge Paulino demanded that the defence lawyers show some respect for Razaco, adding that they were not obliged to like or believe her.