Tullow Oil's chief financial officer (CFO), Ian Springett, has resigned with immediate effect from the board of the oil explorer.

Mr Springett is being replaced on a full-time basis by Les Wood, who took on the role of interim CFO on January 5th, 2017, when Mr Springett took an extended leave of absence to undergo treatment for a medical condition.

Mr Wood joined Tullow in 2014 and was the group's vice-president for commercial and finance before being appointed interim CFO. Before joining Tullow, Mr Wood worked for BP for 28 years in various positions including regional CFO roles in Canada and the Middle East.

Tullow Oil chairman Aidan Heavey said: "I am very sorry that Ian's medical condition has led to his decision to step down from the board. He has been an invaluable and highly regarded colleague and friend since he joined the board of Tullow back in 2008. His financial acumen and industry expertise were evident from his first day as chief financial officer and he will be greatly missed. We wish him continued success in dealing with his illness."