The Serious Fraud Office served Hanover Finance director Mark Hotchin with papers to supply company documents when he visited New Zealand last week because it does not have jurisdiction to do so in Australia.

The SFO announced on November 29 it was investigating Hanover Finance and had been doing so for three months.

But Hotchin has been based on the Gold Coast and because the SFO does not have extraterritorial rights in Australia, a warrant to supply information would hold no legal validity there, SFO chief executive Adam Feeley said.

He would not comment on how the SFO knew Hotchin was back in New Zealand or what documents it was seeking from the former director.

"We have issued notices to a lot of people related to Hanover Finance. The gist is to supply us with all documents in their possession, including electronic data."

Feeley said because the SFO's power is limited in Australia it has three options to gain information: serving people when they re-enter New Zealand, through voluntary compliance and through mutual assistance with a similar agency based overseas.

Although, Feeley said, the last-mentioned was a final resort, the SFO has worked with agencies in the United States, Britain and Australia when investigating alleged fraud.

Last month, the Securities Commission froze Hotchin's New Zealand assets.

At the time, the commission said the unprecedented move was fuelled by a desire to collect money for investors in case any civil claims were brought against Hanover and Hotchin.

Details of what assets were frozen have not been publicised - but Hotchin is trying to have the order revoked.