The group have recruited City law firm Field Fisher Waterhouse to advise members on possible legal action.
The group claims the investment was sold as an instant access deposit account.
They are also calling for a postponement of the decision deadline for policyholders to decide whether they are going to withdraw their funds and take a loss of up to 25 per cent of their remaining deposit or whether they will remain in the fund until 2012 to guarantee their deposit.
Investors can also choose the conditional exit and withdraw their funds only if assets reach a specified auction price.
The threshold for the conditional exit plan has now been set at 66 per cent of the policyholder’s remaining enhanced fund holdings.
AIG action group chairman Zia Khan says: “we will fight AIG and the banks for our members until they receive all their money back.
“Many of them are now suffering as all their cash was in the fund.”