Online attacks on public health advocates have been condemned in the British Medical Journal, with New Zealand cited as an example of dirty tricks campaigns.
In an opinion piece in the publication Martin McKee, professor of European Public Health at the London School of Hygiene and Tropical Medicine, cited tactics described in investigative journalist Nicky Hager's book, Dirty Politics, as strengthening suspicions that large corporations were helping fund internet trolls.
While some online critics were the sort of people "who in the past might have spent their days on a soap box in the marketplace", others were "professionals, paid by large corporations to attack others," McKee said.
Dirty Politics alleged links between Prime Minister John Key's office, National Party politicians and party-linked figures, and WhaleOil blogger Cameron Slater. It was based on emails and Facebook posts hacked from Slater's computer.
Hager's book also made allegations tobacco, food and alcohol companies were paying Slater.
Companies engaged public relations consultant Carrick Graham, the son of a senior National Party politician, who reportedly paid Slater $6555 a month to promote his clients' interests on WhaleOil, and attack those whose work threatened his clients' interests.
Slater has previously denied any claims that he was paid for content.
McKee said advocates of public health policies were paying the price of speaking out, and big corporations were funding campaigns to undermine them.
"Most of us soon realise that this is the price to be paid for taking a stand and refuse to engage with our attackers, whose main aim seems to be to provoke a hostile response that they can ruthlessly exploit," he said.
Attacks of this nature were not limited to New Zealand, but had also been made on British public health professionals, particularly those active in tobacco control, he said.
The anonymity of blogs and Twitter accounts engaged in attacks were cause for the public health community to be suspicious about who was really behind the activities, McKee said, especially in light of Hager's book.
Hager this afternoon said he was "continually pleased to see people raising and debating the issues in the book."
"Half of what the public has heard so far has been controversy and denials, but lots of serious issues are going to keep coming up like this.