Is it safe to accept post-dated cheques to drop a fraud cheque case

Hi,

I invested AED 75,000 with a company that intended a takeover of CCTV installation, and the company is located in DAFZA with 4 partners.

They made me sign an internal contract which wasn't signed by all the partners and I never got a copy of the same signed by all 4 partners.

I kept chasing them for the same as well as for MOA from DAFZA and name change on Trade Licence but got only excuses.

Finally, after 3 months of chasing them, they informed me that they don't intend to take over the company and wanted to divert my funds elsewhere.

I refused and asked for a refund. They gave me a fraud cheque that got bounced due to the unauthorized signatory. I filed a police complaint, after which the authorized signatory was summoned by police.

Later the signatory contacted me and wanted to settle it in 4 PDCs across 3 months but on a condition that I return him the fraud cheque which is the only proof I have proving his fraud intentions.

Kindly advise if his demand for the return of fraud cheque is valid?