need opinion on a issue im facing at my company

im working as a geologist for a mining company. office at kl, site at pahang. The highst person incharge at site is my boss nephew (27yo pmr drop out), who's practically running the mine as well as being HR n Finance supervisor. Being the only educated guy there, i help him with most of the jobs in terms of paper works and admin.

So, he holds the petty cash and handle all purchasing claims. Since he cant read english, he would ask to take the receipts and make sure the purchased items and goods are well in order. As this continues for 2 months, we found that 11k worth of receipts missing. He blamed me for loosing those receipts, while i claim that he never gave to me.

After 1 week, he said he'll cover on behalf by submitting a single receipt worth 7k and ask me to repay the balance amount in cash. I agreed, since the boss wasn't aware of this issue and i don't want to get fired.

I dragged on and delaying the payment for several months, but now i feel that i should't be responsible for the missing receipts as im not hired or get paid to do those works. His salary is 7.5k while mine is 2.5k. So i feel its unfair that instead of paying out of his own pocket, he replace with some receipt and then ask me to pay the balance by cash. Meanwhile, sine he has to show petty cash account to the company, he used his own money to cover the shortage of cash/receipt.

So, the issue is there's no proper document detailing this problem. And i don;t want to pay whatever amount as im being victimized here. Legally, what can i do? If