Sri Lanka's cricket board have forwarded the official report on Muttiah Muralitharan's doosra to the International Cricket Council, board president Mohan de Silva confirmed on Saturday.

"The report from the University of Western Australia was sent with the observations of the bowling review group to the ICC on Friday," de Silva told Reuters. "The details of the report will now be circulated by the ICC to their officials."

Muralitharan's doosra, a delivery that turns in the opposite direction to his stock off break, was reported at the end of the recent Sri Lanka-Australia series by ICC match referee Chris Broad.

The contents of the report have not officially been made public but sources privy to his assessment said biomechanics experts believed Muralitharan should be allowed to bowl his doosra even though his arm straightens by about 10 degrees.

However, the ICC stressed on Tuesday: "The existing regulations governing the degree to which a spin bowler can straighten his arm or 'level of tolerance' (five degrees) remain in place and will be enforced.

"...should any bowler be reported for a second time within 12 months of the first report, the ICC will convene a hearing of its own Bowling Review Group which has the power to impose a ban of up to 12 months should it determine the bowler's action is illegal."

Muralitharan has continued to bowl the doosra during the one-day series against Zimbabwe against the advice of Sri Lankan cricket officials.

Muralitharan, who has taken 513 Test wickets, is on the verge of overtaking West Indies' Courtney Walsh (519) to become the game's leading wicket-taker.

After being reported Muralitharan was sent to Perth for tests where he bowled in front of 12 cameras with his body strapped in reflective markers so a computer could track his action.

Muralitharan's arm straightened by approximately 10 degrees when bowling the delivery. ICC regulations state that pace bowlers are allowed 10 degrees of flex, medium pacers 7-1/2 degrees and spinners five.

Professor Bruce Elliott, an ICC-approved biomechanist who oversaw the assessments, has suggested that further research needs to be undertaken to ascertain whether the levels are practical.