The family of a man who blew the whistle on a murder plot then killed himself when he was accused of the crime, have welcomed a review of the case concluding he was wrongfully charged.

Brian Carter was hailed a hero by officers after walking into Brownhills police station in January 2004 to tell them he had been approached to carry out a contract killing.

He handed over tapes and conversations in which the murder had been discussed, along with more than £1,000 which he said was a down payment for the killing. According to Mr Carter's mother Linda Hulme, her son was praised by police for helping to save the life of the intended 'hit' and taking a gun off the streets.

But later that month he and another man were charged with conspiracy to murder and firearms offences. He was remanded in custody and was awaiting trial when he committed suicide.

Mrs Hulme said as a result of the charges, her son became known as 'an informer' and had feared for his safety and that of his family. She was given a police panic button and in Birmingham Prison her son was placed on a wing for vulnerable prisoners. He was later moved to Shrewsbury Prison, where he hanged himself in March 2004.

David Blundell, chief prosecutor for the West Midlands, reviewed the CPS's decision to prosecute Mr Carter and concluded he would not have charged him with the offence.

Mrs Hulme added: "If he hadn't been charged, he wouldn't have been in prison and known as an informer.

"He went to the police because he thought it was the honest and true thing to do. When he was named as an informer, he was finished."

An inquest into his death recorded a verdict of suicide, due in part to faults in the prison system. It heard Mr Carter, who had been in prison at least three times before, had a history of depression.

Before going to the police Mr Carter had spent two weeks planning the hit in detail with the associate who had approached him.

"The notes indicated this was a case that had been very carefully analysed," Mr Blundell said. "It was difficult and not made quickly." He added: "I would not have made that decision."

Mr Blundell said the legal mechanism to establish whether the CPS decision had been justified had halted with Mr Carter's death.

"If due process had continued he would have been found guilty or acquitted. It is impossible to make a link between his being remanded in custody and him committing suicide," he said.