The Anti Corruption Unit (ACU), the organisation created by the International Cricket Council (ICC) to rid the game of match fixing, is investigating Pakistan's defeat in the opening game of the ICC Champions Trophy, when they lost to Sri Lanka by eight wickets.

Although ACU activities are supposed to remain confidential, the ICC confirmed that specific events during the course of the match had warranted further investigation.

"The ACU has confirmed that as part of the security protocols put in place for the event, it has requested that the host broadcaster supply it with tapes of all matches played," said an ICC media release.

"Specifically, it has reviewed a number of incidents that took place in the opening match of the tournament between Sri Lanka and Pakistan," it added.

"Any incident that looks sub-standard or out of the ordinary, such as a bad run out or bad shot may be looked at," ICC media manager Mark Harrison added.

But he played down the news: "They are just putting into action the process that is now in place. There is nothing out of the ordinary in them requesting a tape."

The ACU has implemented several security measures in the past year, including the appointment of permanent security managers at every game, tight controls over the use of mobile phones by the players and video surveillance at the venues and team hotels.

ACU head Lord Condon claimed: "The ACU is confident that this regime is providing and effective and professional deterrent that will protect both the integrity of the tournament and the privacy of the players."

The ACU are already investigating Pakistan's surprise defeat against South Africa in the Morocco Cup last month, when Waqar Younis's team collapsed from 92 for two to 188 all out, losing the game by eight runs.

Pakistan captain Waqar Younis, speaking to journalists on Sunday night, defended his team: "I am not in a position to comment on the whole issue. All I will say is we have played our cricket in an honest manner."

© CricInfo