Bulgarian authorities have said to own around 200,000 BTC, which I personally find very questionable.
It was worth over $3 billion at the time it was reported, but I don't believe any of this and think it's just another anti crypto campaign to unleash fear. Governments aren't shy of these practices.
The central bank of Poland once financed an anti crypto campaign on social media, and this might be the next thing from that region. I don't doubt they seized a certain amount of Bitcoin, but this is just insane.
It doesn't even sound convincing. I'm not sure if any business or organization performed blockchain analysis in an attempt to locate these wallets, but I would definitely be interested to see the results.
The number of coins it concerns as a whole is too significant to not be a somewhat easy to locate target.