Graham Calvert, 28, says the firm ignored his pleas to bar him from using its telephone betting service.
The greyhound trainer claims it allowed him to gamble £3.5million in a matter of months.
In a landmark case due to be heard at the High Court next week, he claims William Hill negligently allowed him to amass losses of £2.1million.
Read more: http://www.dailymail.co.uk/news/article-514309/Compulsive-gambler-sues-William-Hill-letting-lose-2million.html#ixzz0OtjWemSz
