Tougher rules are needed to combat the risk of political corruption in New Zealand, according to the Helen Clark Foundation.

In a report for the public policy think-tank, set up by former prime minister Helen Clark, author Philippa Yasbek set out 26 recommendations to strengthen the country's anti-corruption measures.

They included penalties for those who failed to comply with the Official Information Act, capping a person's political donations to $30,000 per electoral cycle, mandatory reporting of all gifts offered to politicians, and a three-year wait before any former politician could become a lobbyist.

"Corruption is an insidious cancer. It is not enough for democracies like ours to pay lip service to principles of transparency and steps which need to be taken against corruption," he said in a foreword to the report.

"New Zealand must critically examine these issues on a regular basis. That is why this article is so important and why it raises very serious questions about New Zealand's current commitment to transparency."

Yasbek said anti-corruption measures in New Zealand were largely governed by social norms, but laws were needed.