Dr Graham's views will be seen as a blow to AstraZeneca, which has been trying hard to reverse a sales slide of its anti-cholesterol drug which began when its safety was first publicly questioned by the scientist last November.
Dr Graham said during an interview that Crestor had a "unique toxicity", caused by the fact that, in a small number of patients, it has two adverse side-effects: muscle wasting and kidney failure. For this reason, Crestor should only be used "as a second-line drug when people have failed to respond to other statins", Dr Graham said.
"Why would you push a drug that you know has potentially a high risk of muscle disease and renal failure when there are other drugs that you know work well?" Dr Graham said.
AstraZeneca strongly rejects Dr Graham's views. Gunnar Olsson, the head of cardiovascular therapies at the company, said Crestor had a "very good efficacy in lowering bad cholesterol and increasing good cholesterol and, at the same time, has a safety profile that is very much in line with all other marketed statins".
He added that other statins - a class of drug used to prevent ailments including chest pain and strokes - also had side-effects which could include both muscle wasting and kidney failure.
Crestor has been on the market in the US and UK since 2003. After Dr Graham first told a Senate hearing in November that Crestor was one of five drugs which required further testing, AstraZeneca's share of the anti-cholesterol drug market in the US fell from 8 per cent to 6 per cent. AstraZeneca's target for Crestor is nearer 20 per cent.
The scientist, who works in the FDA's office of drug safety, emphasised his opinion was a personal one and not the official view of the agency, which is still evaluating data being collected now Crestor is on the market.
Dr Graham's relationship with his employer has become fraught after a series of damning remarks he has made about the FDA's handling of issues surrounding Vioxx, the arthritis drug made by Merck.
The US pharmaceutical company withdraw Vioxx in September after scientific studies showed the drug increased the risk of heart attack.
Yesterday Merck defended itself against new claims that it tried to persuade doctors sceptical about Vioxx to offer the drug by offering them consultants' jobs and other perks.Reuse content