Financial services regulators have enough clout to send shivers down the spines of the biggest banks, investors and hedge funds alike.

They have frequently shown they are not afraid to wield their power in the defence of best practice in the financial markets. Not very inspiring and somewhat embarrassing then, when a senior member of staff at German regulator BaFin is arrested for taking €2.6m ($3.2m) in bribes that helped fund an extravagant lifestyle of fast cars and plush apartments.