My brother was detained in Sharjah Airport for an old bank debt that he settled

My brother was detained last week in Sharjah Airport when he was traveling from Saudi Arabia stating there is a cheque bounce case.

Further, looking into details we found that there is an open case in his name raised by a bank that issued a credit card to my brother when he was working in Abu Dhabi back in 2018.

There was a credit card payment due when he moved back to his home country from Abu Dhabi in 2018. Later, he coordinated with collection people and settled the matter by paying dues.

There is an email communication evidence in 2019 from bank officers that all dues are paid and settled and they will issue a clearance certificate which we never got.

The settlement has happened with the bank but the police case was never closed as it seems. Now my brother is in jail for no fault. He is taken to Abu Dhabi and now planning to take him to Dubai for the court appearance.

What should we do with this situation?

My brother is facing all this trouble for no reason.