For an 11-hour sitting at Monte Carlo Casino in July 1891, a man named Charles Wells had an exceptional winning streak. In a run of 30 spins on the roulette wheel, he won 23 times.

The Englishman had walked in with £4,000 and left with a million francs, roughly the equivalent of £12m today.

In casino-speak, when a player at Monte Carlo won more money than a table had in its cash reserves, the player had “broken the bank”. In his single sitting, Mr Wells did this 12 times.

Much to the dismay of the croupier, he came back four months later. Over a period of three days, he won another million francs.

This piqued some serious suspicion. Mr Wells was trailed by private detectives hired by the casino, but they could find no proof of underhand dealings.