Presenting evidence for deceit in defence of a bounced cheque case

I need guidance regarding a civil case against my brother for issuing a cheque of AED 270000 having no sufficient amount in his account.

The other person made some trade deal for selling precious stones to my brother and he took advance cheques from my brother and advance signatures on the invoice, LPO and delivery note.

My brother trusted him but later he did not deliver anything to him and rather started blackmailing my brother to give the money otherwise he will make a civil case against him.

My brother refused to pay any amount for the deal he never received, which resulted in making proper legal documents by the opposite party against my brother through a lawyer and made a civil case against my brother in Sharjah.

Now, my brother is in Sharjah central jail since Jan 2017. Every month, he appears in the court and the judge asks him to pay money but he refuses every time & requests to call the opposite party to the court. However, neither he nor his lawyer appeared the last 10 months in court. I need guidance.