Requiring to pay Personal Income Tax by trading platform - fraud or legitimate?

[Jeffster]

I have been trading Spot GOLD Nodes on MT5 platform support by Evest.Life (Evest Group Ltd., registered UK corporation) for the past 4 months. all of a sudden they froze my account and would not allow me to trade or withdrawal and requested that I pay 20% of "Personal Income Tax" of my gains. They claim that the tax bureau has found that I have not paid personal income tax and hereby informs me that I need to pay personal income tax else my account remains frozen.

Does this sound off and more lending towards Fraud? Or is this a practice in UK or specifically trading platform(s) such as this one?

[shades]

If you don't hold it in your hands, you don't own it. Might want to go with physical in hand to avoid being on govt confiscation schemes. Will only get worse in the future.