The Commerce Commission today refused to comment on whether it has received a complaint that Countdown demanded a $2 million retrospective payment from a supplier as part of its investigation into the supermarket giant.

The competition watchdog was quizzed on the claim as it appeared before MPs in Parliament this afternoon.

Labour MP Clayton Cosgrove asked commission chief executive Brent Alderton whether he could confirm that "a complaint of a $2 million retrospective payment was made to the commission" and that "once it reached your desk, that complaint effectively vanished because Progressive went to the supplier and basically said it was a big mistake, that they didn't want $2 million?"

Mr Alderton said said it would be inappropriate to comment given the commission's ongoing investigation into allegations made by Mr Cosgrove's colleague Shane Jones that Countdown and its Australian owned parent had bullied suppliers into making such payments.


Similarly, Mr Alderton refused to comment when asked how many complainants who had come forward so far had been threatened by reprisals by Countdown.

But Mr Alderton did respond when Mr Cosgrove asked if he could confirm that the commission had received in excess of 30 complaints from suppliers, telling him that was not the case.

He indicated that not all complaints received so far were about Countdown, but said that company's practices remained the focus of the inquiry at this point.

The commission has seven investigators working on the investigation which is expected to take several months.

Mr Alderton answered questions on the supermarket probe as commission chairman Mark Berry said he may have a conflict of interest on the matter. Dr Berry told the committee while in private practice as a lawyer few years before, he acted for suppliers over similar complaints.

The commission last month said it would formally investigate Mr Jone's complaint of anti-competitive behaviour by Countdown, and encouraged suppliers to come forward, promising anonymity for those who sought it.

Countdown has denied the allegations and says it will co-operate fully with investigation.