The Commerce Commission's case against Bunnings' alleged misleading advertising over its "lowest prices guaranteed" campaign has been dealt a blow by The Court of Appeal.
The Court ruled the commission would not be allowed to use a witness statement from a Mitre 10 manager who was giving evidence of an automated price comparison survey undertaken by Mitre 10 between June 2015 and May 2016.
Bunnings pleaded not guilty after the commission laid 45 charges in December 2016 of misleading the public.
The alleged offending took place between June 2014 and February 2016 and involved print, radio and television marketing campaigns, in-store signs, staff uniforms as well as its website.
A trial is scheduled for September.
This month it was revealed by the Herald the commission had spent $950,475.28 on the case so far.
Staff at the state watchdog had spent 1137 hours investigating the case and a further 1441 hours on litigation.
External legal services made up the lion's share of state money forked out. That cost $885,000 and travel nearly $3000.
The commission's investigation started in April 2015.
In May 2018, Bunnings' application for disclosure of documents was dismissed in the Auckland District Court.
In August 2018, the District Court ruled evidence from Mitre 10 admissible.
In September that same year, the High Court dismissed Bunnings' appeal against the District Court's disclosure decision.
In February last year, Bunnings sought leave to appeal the High Court's disclosure decision. That application was dismissed last March, the spokesman said.
Just before Christmas, the High Court dismissed Bunnings' application for judicial review of the District Court's decision regarding a summons of Mitre 10, and admissibility of information from Mitre 10.
In April this year, the High Court denied Bunnings' application to have the High Court's judgment recalled.
Each of the 45 alleged offences is punishable by a fine of up to $600,000.