The hacker "Rawshark" has released emails that appear to back up claims in Nicky Hager's book Dirty Politics that the Whale Oil blog was used to attack critics of a grocery lobby group.
The release of information comes amid claims by the former National minister Judith Collins that previously released social media messages between her and the Whale Oil blogger Cameron Slater are fabricated.
The information released this afternoon purports to show the blog attacking those causing problems for the Food and Grocery Council, which is headed by the former National MP Katherine Rich.
The emails appear to support allegations made in Mr Hager's book that a public relations executive, Carrick Graham, helped Mrs Rich organise articles critical of groups raising health concerns over the use of sugar.