After suspending a top member for corruption, Umno said that it was committed to fighting graft, but a culture of silence among fearful members made it a difficult battle.

"The Umno leadership wants to see money politics eradicated. How far we are successful depends very much on Umno members themselves... to come forward and tell us what really is the problem," said Tengku Ahmad Rithauddeen.

"Without any evidence we cannot start our investigation. So the party members are those who can help eradicate this," the Umno disciplinary board member told a press conference.

Tengku Rithauddeen said members of Umno, the lead partner in the ruling Barisan Nasional coalition, were afraid to come forward on the issue which has dogged the party for decades.

"People are not prepared to come forward to tell. They are so scared. That is the dilemma we are facing," he said.

Prime Minister Abdullah Ahmad Badawi declared the fight against graft a cornerstone of his administration after coming to power in 2003, but has been criticised for failing to claim many important scalps.

Not a vendetta

However the six-year suspension handed down last week to Federal Territories minister Isa Samad - the most senior member targeted so far - marked a dramatic revival of the campaign.

He was found guilty of vote-buying during the party's fiercely contested leadership elections last September.

Tengku Rithauddeen denied Isa was the target of a vendetta or was being made the scapegoat for the corruption that is endemic within the party.

"There is no political conspiracy. There is no political vendetta," he said.

Tengku Rithauddeen said about 30 witnessess gave evidence against Isa and the disciplinary committee's investigation into the minister, who also serves as Umno vice-president, began in October 2004.