A student is suing one of Britain’s biggest bookmakers for refusing to pay out £1 million on a winning bet on the horses.

In a battle of David vs Goliath proportions, Megan McCann, who was just 19 when she placed the bet, has lodged a writ in the High Court in Northern Ireland against Hillside (UK Sports) LP, the company which operates bet365, an online betting company run by the UK’s wealthiest businesswoman.

Miss McCann, who lives near Belfast, claims that she is owed £1,009,960 by bet365, which was co-founded and run by Denise Coates, who is said to be worth £3.2 billion.

Miss McCann staked almost £25,000 on 12 different horses in four relatively obscure races, winning £985,000 from the betting giant. But the betting company, whose chief executive is Ms Coates, has declined to honour the wager.