G’day. Many years ago, I bought some eth. The company went belly up/disappeared. Recently a bloke purporting to be from UK government agency contacted me in relation to this, stating that they had recovered my eth, and asked for cold wallet address, which I provided, and have now received frozen eth into of a substantial amount. He also stated that I need to buy 10% of the value of the deposited eth, and add to the wallet. Then I need to transfer both lots to another wallet in my name, which will thaw/unfreeze the eth in the process. I suspect this is a scam, but I can find no evidence either way. I await your guidance.
Hang on, the very first line: you bought some but the company disappeared? You mean you paid some kind of exchange but didn’t bring it to your own wallet, just left it in an account? That probably means no eth was actually yours in the first place, they just had a bookkeeping entry that you owned a share of the exchange’s holding. But when the exchange goes defunct, the exchange’s holdings are just gone and no blokes from government agencies can get it back.