That’s not really true though is it?
Plenty of governments around the world who might be classified as corrupt have laws drafted in such a way that their corrupt dealings falls outside criminal sanctions.
It doesn't really look like a shady deal though because the office building they bought was already owned by an overseas company, they didn't insist on the deal be structured in such a way, and it was brought into UK tax regime following the transfer.
There might have been other reasons why they might jave wanted to acquire the holding comapny as a going concern before dissolving it into their own company. Contracts for maintenance and security etc may have been kept, rather than void them and renegotiate new terms.