The Australian Competition and Consumer Commission has turned down a request by iiNet to privately brief ISPs on how wholesale prices for Telstra DSL ports are calculated.
The Perth-based ISP had been pushing for a private briefing since mid-April to glean information that would have allowed it to test the assumptions used by the ACCC to calculate new wholesale pricing.
The ACCC last week handed down the final prices, which apply until the end of June 2014.
In a separate letter response (pdf), the ACCC said it had decided against holding a private briefing as requested by iiNet.
"The need to provide a transparent and effective consultation process that allows interested parties to effectively and independently scrutinise the ACCC's reasons is an issue that the ACCC takes seriously," it said.
"Transparency must, however, be balanced against the access provider's legitimate interests in protecting its commercially sensitive information."
The ACCC indicated it is "considering some practical options" to deal with similar issues it expects may crop up in a review of fixed line services, due to start later this year.