Australian spin bowling legend Shane Warne says he agrees with calls for life bans for anyone found guilty of match fixing.

Pakistan captain Salman Butt and fast bowlers Mohammad Amir and Mohammad Asif are under investigation by police in London after being accused of throwing matches and intentionally bowling no balls at specific times to influence betting.

Warne, who took 708 test wickets for Australia, said the ICC needed to take a zero tolerance stance on the issue.

"They should be thrown out, simple as that,'' Warne said.

"I don't think there is any other way to do it, if they have been involved in throwing games."

"They should be banned for life ... anybody who is involved should be thrown out.''

Inconsistent form has long been a staple of Pakistani cricket, but Warne said he could understand how that could be a cover for something more sinister.

"Pakistan are such a hot, cold team," Warne said.

"One minute they are on song and the next they're not and we were watching going 'This can't be happening, what are they doing?'"

"We thought there must have been some method in their madness but to think back now, if it's true what they are saying... if it was fixed, you could understand. It would make sense.''

The ICC and the Pakistan Cricket Board have both launched investigations into the allegations against the players at the centre of the scandal, and Warne said it was time for the game's governing body to be decisive.

"You would hope they can flex their muscles and show they do run the game,'' he said.

Pakistan is scheduled to play a limited overs tour match against Somerset on Thursday ahead of its upcoming one-day series against England.