[eljot88]

Hey,
so I let a refunder to make a refund on Amazon.es. I ordered item worth 700 eur on aged account with one previous order. Got OFM warning. Now he told me, he sent them a fake police report. I wanted to ask if I should cancel asap the police report and return the item? I heard it's risky, but also I heard they don't call police or something.

So they denied your PR. If they sent you only an ofm email warning, then you are in good situation. Just start the return process and sent the item back. When they receive the item, you will receive your money back. Easy.
But the account is flagged so don't use it for further refunds.