A television programme is to claim that rules for granting Public Interest Immunity to prosecution witnesses were established during a case in which three men were wrongly convicted.

Raphael Rowe, Michael Davis and Randolph Johnson were wrongly convicted of murder, robbery, grievous bodily harm and firearms offences in 1990.

The case was built around information given by three informants who were granted immunity. No forensic evidence was used in the case.

Rough Justice, to be screened on Wednesday night, alleges the police dropped prosecutions against the informants, whose fingerprints were on the stolen goods in question, and paid them a reward in return for co-operation. But the BBC programme alleges that immunity meant that these facts were withheld from the defence.

The case is now being reinvestigated by the Criminal Cases Review Commission and goes before the European Court of Human Rights next year.

The use of informants in criminal cases has increased since 1990 with practical rules for granting immunity being based on the Davis/Rowe case.

Changes brought about by the Scott Report only relate to ministers granting immunity.

Liberty legal officer Mary Cunneen, who is handling the case before the European Court of Human Rights, said: “Immunity breaches a defendant's right to a fair trial. The defence cannot say to the jury “why is this witness giving this evidence?' If this continues, more miscarriages of justice will result.”