Banque Havilland, the Luxembourg private bank of David “Spotty” Rowland, and considered very much his own personal piggy bank, just can’t stay out of the headlines.

Prince Andrew is a patron of the bank, starring at its opening ceremonies some years back, it should be noted.

Now, Qatar is suing the ex-Conservative treasurer’s Havilland at the High Court, claiming that his bank had a role in a conspiracy to undermine the Gulf state by manipulating financi...