Investors have been sent a 16-page questionnaire, asking them about their involvement with Ross, whether they knew him before investing, their investment experience,  the fees they paid, what instructions they gave to Ross, what bank account they deposited funds into and what information they received.

Receivers have so far only found about $1.1 million of the $450 million Ross investors through they had.

Financial Markets Authority manager of evidence Jason Lunjevich said the information gathered from the questionnaire might be disclosed to the Serious Fraud Office.

RAM Investors Group spokesman Bruce Tichbon said it was the first time he had seen a questionnaire like it.  “It’s very detailed, asking for specific information.”

He said the FMA had told him that it wanted a high-level view of the situation and the responses could lead to other actions, such as prosecution of Ross.

Tichbon said the issue for investors was why it had taken so long to get to this point. “These questions would have been reasonable one month after the collapse. To trot it out six months on is bordering slightly on the bizarre. You have to wonder if the system is dysfunctional.”

He said he would be telling the more than 400 members of the investors group that they should fill it out and continue to co-operate with the FMA.

“It’s so far from answering the basic questions: Where has our money gone and can we get it back?”

FMA spokesman Tony Reid said his organisation had given the Ross investors regular updates.

"We have reached a point in the investigation process where further consolidated information is now required in the form of a detailed questionnaire. We do understand the frustration of investors who have lost large sums of money as a result of investing their money with David Ross. Our focus is on getting the best outcome for these investors, and the best way we can do that is by carrying out a thorough and proper investigation."