At this weekend's Hay festival, mafia expert Roberto Saviano said dealings in London's financial services sector make the UK the most corrupt nation in the world.
The Guardian reported this weekend that the banking sector creates "criminal capitalism", allowing drug money to be laundered offshore.
"If I asked what is the most corrupt place on earth, you might say it's Afghanistan, maybe Greece, Nigeria, the south of Italy.
"I would say it is the UK. It's not UK bureaucracy, police, or politics, but what is corrupt is the financial capital. 90 per cent of the owners of capital in London have their headquarters offshore," he said.
He added that a vote for Brexit will cause the situation to worsen.
"Leaving the EU means allowing Qatari societies, the Mexican cartels, the Russian Mafia to gain even more power."
Saviano isn't the only one to have taken that view in recent days. In an interview with City A.M. last week, David Cameron's former adviser Steve Hilton branded the banking sector a "stitched-up, corrupt cartel" which needs to be completely overhauled (to be fair, the Panama Papers hasn't helped...).
However, Hilton made the case for a Brexit, saying the UK doesn't need "busy-body, macro interference by regulators who don't know what's going on".
That said, a ranking of the best and worst countries to do business in ranked the UK at a respectable (although not sterling) 20th position in the world, thanks in part to low corruption levels.
FM Global's Resilience Index, published earlier this month, ranked Switzerland as the top country in the world to do business, followed by Norway and Ireland.
Meanwhile, Venezuela was named the worst country in the world to do business, followed by the Dominican and Kyrgyz Republics.