Jacque Alderson from the University of Western Australia said it would be difficult for the Sri Lankan spinner to deliberately change his bowling technique without the biomechanic's team detecting a slowing down of action.
Her comments come after Australian vice-captain Adam Gilchrist questioned the value of the testing procedures.
"I have got to question why they bother doing a test like that, whether it is Murali or anyone else in world cricket," Gilchrist told Channel Seven on Monday. "Because there is nothing similar between that in a laboratory and what you are facing in the Test matches."
Gilchrist has been in trouble in the past for commenting on Muralitharan's action, being reprimanded in May 2002 by the (then) Australian Cricket Board for calling him a chucker.
"What I find interesting is they say you don't need to look at his general off-break any more because we have cleared that," he said.
"A bowler can change what they want, every single delivery in a Test match, whatever they want to do with their wrist or the arm. I don't see that you can say they are cleared, we don't need to look for it anymore."
Alderson, who sent the biomechanics report on Muralitharan's "doosra" to the Sri Lanka Cricket on Tuesday, said the testing was not without flaw.
Murali's doosra ball turns away from the right-handers unlike his stock ball that comes into the batsman.
"I think it would be highly unlikely that someone will be able to change their action inside that environment but I would not say it would be impossible," she said.
"But to be honest I don't know any other way it could be tested. You would have to say it would be very difficult for someone to actively change their motion in less than one-hundredth of a second."
She said it took the same amount of time for Muralitharan to rotate his shoulder in lab testing as in match conditions.
"The time period it took within the lab to rotate was the same as it has been in a match condition, and that is probably the only validity check we could make," he said.
Muralitharan has captured 513 wickets in 88 Tests and is now only six wickets short of West Indian Courtney Walsh's world record, which he is expected to eclipse during this month's two-Test series in Zimbabwe.