Ranatunga, who led Sri Lanka to an epic triumph in the 1996 World Cup, felt the prolific off-spinner was being put under pressure just when he was set to become the highest wicket-taker in Test history.
In remarks published in the Island newspaper, Ranatunga said he saw a conspiracy against Muralitharan, who is just six wickets short of retired West Indian paceman Courtney Walsh's record of 519 wickets.
"This is to totally discredit the achievements of a great player. Murali is chasing the world record with Shane Warne (of Australia) and the Australians and the English do not want one of our players getting there," he said.
Muralitharan was reported to the ICC after the third and final Test against Australia on Sunday by match-referee Chris Broad, a former England Test batsman, who doubted the legitimacy of one of Muralitharan's deliveries.
Broad said the bowler's 'doosra', which turns away from the right-handers unlike his stock ball that comes in, needed more looking into. Broad added that he had discussed the matter with umpires Dave Orchard and Steve Bucknor and they were fully aware of the situation.
Ranatunga criticised Broad and said his appointment as match referee was a let down for the game.
"The ICC should appoint those who are experienced, with an impeccable record in such responsible roles," Ranatunga told the Island newspaper. "What experience does Broad have? Look at his background. His appointment and what he has done is a let down to the ICC's reputation."
The newspaper said Ranatunga was hinting at a "white conspiracy" against Muralitharan who finished the series against Australia with 28 wickets to take his tally to 513.
"This issue now comes under the ICC's regulations dealing with this matter and over the next six weeks an expert bio-mechanist will be appointed by Sri Lanka Cricket to work with the bowler to clearly identify and address any flaws that may occur during the delivery action," an ICC statement said.
"Muralitharan will be able to continue to play during this time." It added that the match-referee reviewed Muralitharan's new delivery and after examining the action closely decided to report him to the ICC and notify the Sri Lanka Cricket.
Muralitharan was three times called for "chucking" by Australian umpires before being cleared by bio-mechanical experts, who concluded that he suffered from a congenital condition that prevented him from straightening his elbow.
He is the fourth player to be reported to the ICC under its revised process to deal with potentially flawed actions in the past 12 months.
West Indies' Jermaine Lawson, Bangladeshi Sanwar Hossain and Pakistani paceman Shabbir Ahmed have already been asked to undergo remedial work on their bowling actions.