SCAM Alert! I am out US$186K

I have invested $140K on this trading platform
The money had grown to $186K in a couple of months. When I tried to withdraw a large amount of money ($140K) from it, a day anf a half would pass with no money sent! They insisted the request had been approved and the funds released to the destination account (Coinbase). Indeed the status states "Already withdraw.." But still no money at Coinbase. Then they told me they found some "anomaly" in my account and demanded I deposit $100K into the account for security purposes before they would restore my withdrawal rights!