How can we access the bank account of a deceased person?

My uncle died 2 weeks ago in one of the private hospitals here in Dubai.

We have already completed everything regarding the repatriation of his body with the help of his employer and his remains are already sent back to our home country last week.

He used to give me an access of his ATM card before and I tried to access it just few days ago and I found out that there is some amount of money left on his bank account.

I am aware that he has some pending bank loan requests before he died, so I am afraid that amount might be the reason of such big amount.

Being the only family member of my deceased uncle, what should I do in order to make sure that the amount is from his savings and not from his bank loans?

In case the amount is proved to be his own savings, is there any chance for me to get the authorization to claim that amount from the bank to be used by his family?

He has a wife with 3 kids back home.

Thanks a lot in advance.