The Commerce Commission will not widen its investigation to include other supermarkets following allegations raised by MP Shane Jones against supermarket group Countdown.
In February, speaking under the protection of parliamentary privilege, Jones accused Progressive of demanding cash payments from Kiwi suppliers.
Progressives has "categorically" denied Jones' claims.
Chief executive Brent Alderton today said the commission had received "a number of complaints" against Countdown, owned by Progressive Enterprises, since it launched its investigation.
Under questioning from Labour MP Clayton Cosgrove at a parliamentary committee, he said fewer than 30 complaints had been made and that most related to Countdown and Progressive.
There had also been some general industry complaints, but it was not appropriate to widen the probe, he said.
Seven staff were allocated to the investigation which he expected would take several months to complete.
Kiwi suppliers had said they were summoned to meet Countdown management and told that if they did not make cash payments, they faced permanent exclusion from the shelves, Jones said. Likewise, if they revealed the meetings to anyone, they would be "blacklisted".
Cosgrove asked several questions related to those allegations today.
Alderton said it was not appropriate to disclose the nature of complaints
He could not confirm other matters put to him by Cosgrove at the committee, including whether there had been a complaint of a demand for a $2 million retrospective payment.
Cosgrove asked Alderton whether "once it reached your desk ....[it] effectively vanished because Progressive went to the supplier and basically said it was a big mistake - that they didn't want $2 million?"
Alderton guarantee anonymity to complainants and said information would only be disclosed if required by law.
Cosgrove declined to comment further on his questions outside the committee.
"You've seen from the Commerce Commission that they now have a series of complaints. This has gone from an issue of hearsay to a formal inquiry. That shows the gravity of the issue."
Asked if it was right to assume he was on a fishing expedition, Cosgrove said: "You're a journalist, this is a democracy you can assume what you will."
- Fairfax Media