ALLEGED stun gun killer Sarah Williams had an affair with a third ski instructor while still in a relationship with her 75-year-old long-term lover, a jury has been told.

Williams, 35, accused of murdering love rival Sadie Hartley, 60, first became a couple with married father David Hardwick when she was 17 and he was 57.

Preston Crown Court has already heard that Williams embarked on an “intense, passionate” affair from June 2011 to April 2012 with married Thai martial arts gym owner, Somapat Sitiwatjana, 47.

Williams’s affair with ex-fireman Ian Johnston began in September 2013 and eventually led, the prosecution say, to the defendant stabbing to death his partner, Ms Hartley, after he refused to leave her and she wanted Mr Johnston to herself.

The ski travel firm sales adviser allegedly drove to their home in Helmshore and incapacitated Ms Hartley with a 500,000-volt stun gun before she launched the frenzied attack.

Yesterday, the jury was read a statement by ski instructor, Andy Poole, who confirmed he had a year-long relationship with Williams starting in 2012 - months after they met at the French ski resort of Tignes in January that year. Williams, of Treborth Road, Blacon, Chester, denies murder.

Trial continues