A DAD who has been fighting for 19 years for a full-scale investigation into the death of his son is vowing to battle on for a public inquiry.

William Powell stressed it was important to win a judicial review challenging the General Medical Council's (GMC) decision not to investigate after 10-year-old Robbie died. The step was won, after the charity Action against Medical Accidents (Avma) took the case.

Robbie died after doctors failed to detect he had Addison's disease — a chronic but treatable condition affecting the adrenal glands.

But Mr Powell, of Ystradgynlais, said he would continue to lobby First Minister Rhodri Morgan in an attempt to win the public inquiry.

An Assembly spokeswoman said the move was being actively considered, and Mr Morgan hoped to make a decision soon.

Mr Powell said: "The judicial review is a great step.

"I have been given the opportunity for a full hearing. If it had not been for the charity, I would not have the hearing.

"But I should not have had to fight for justice for 19 years. At the time, we were absolutely devastated by Robbie's death — it's difficult to watch your son die."

He added: "All I have ever wanted was the truth."

Since 2000, Mr Powell has repeatedly called on the First Minister to hold a public inquiry, with thousands of people signing a petition to support the call.

In 2003, Mr Powell called on the GMC to investigate the case — believing there was a "cover-up" by doctors, who were alleged to have falsified documents to convince others of their competence.

But, in May 2008, he was told it would not be possible, because the events around his son's death in April 1990 happened more than five years before the allegations were highlighted.

But the counsel acting on behalf of Avma, Nigel Pleming QC, told Mr Justice Davis it was wrong in law and that it was irrational for the GMC to apply the five-year rule and to say there were no exceptional circumstances to justify pressing ahead with the case.

In 2004, an inquest jury returned a verdict of natural causes, aggravated by neglect. The youngster had been seen by a series of doctors before he died, the inquest heard, but none diagnosed his condition.

Mr Powell made clear he had not benefited from a payment of compensation, and it had instead been ploughed into his legal costs.

An Assembly Government spokeswoman said: "The First Minister is actively considering Mr Powell's request for a public inquiry, and hopes to be in a position to make a decision soon.

"The decision is made complicated by the need to consider the relationship between the request for an inquiry and the various sets of other proceedings that have been set in train in this case, and the extent to which they have a bearing on the First Minister's decision."