Wow.... Trust, once lost, is very hard to gain back. Did the treasurer go? Did you lose all group funds, some of it, or most of it? I think if you have a clear the air meeting, and put in place structures, you can survive.

@Redondo

From my personal experience .......

Such things do happen in group investments. My advise to you is not to give up.
There must be some serious people in the group for it to succeed.
Selflessness and dedication are qualities required from each member in order for your activities to move forward.
Make sure that the group is registered with the relevant authorities e.g. relevant dept at the Ministry of social services and if it's a coop group with the coop ministry. You must make sure the first officials are people of integrity and see to it that the procedures for deposits and withdrawals from your group account are very strict and at the same time have withdrawal limits.
You do not have to begin with a very big group. Pepople who join later when the group has taken off and is successful should be asked to pay a goodwill. That way you should be able to grow wery fast.