Is chairman responsible for misappropriation of funds by secretary?

I'm the Chairman of the Society, where there is a dispute going on with the society over conveyance amount in which I suspect the secretary may have colluded with the lawyer and got paid. And, there's another thing ie he took my signatures for several payments to vendors but he doesn't has bills for many of them. We, me and treasurer told the Society about this issue but in the SGM they blamed all 3 of us and demanded that all 3 should pay equally. What are my options a