Jack Leach took more Championship wickets than any other English spinner in 2016

Somerset left-arm spinner Jack Leach was not considered for a call-up to England's tour of India because of concerns about his action.

Leach was overlooked as a replacement for the injured Zafar Ansari, with Liam Dawson chosen instead.

Information on his action became public the day after India scored 759-7 in the fourth Test in Chennai.

"When I did the test and they told me, I was as shocked as anyone," said Leach, 25.

Leach took 65 Championship wickets in 2016, more than any other English spinner. He has been part of the England Lions squad for matches against the UAE and Afghanistan and will tour Sri Lanka in the new year.

"It was only a very small thing in terms of my body position," he added. "I've made a hell of a lot of progress and I was pleased with the way it went out in the UAE."

Leach said he had "come to terms" with needing work on his action and that he would be a "better bowler in future".

Peter Such, the ECB's lead spin-bowling coach, confirmed: "He's only made slight modifications but they make a big difference, and we've seen really significant progress".

Matthew Maynard, Somerset's director of cricket, said: "Whilst he was picked up for a minor abnormality in his bowling action during routine testing at the end of the season, this was quickly addressed with remedial work, allowing him to play for England Lions over the last few weeks.

"I have every confidence that he will be playing for England in the future and that there is no major issue with his bowling action."

Leach was not chosen for the tour to Bangladesh, with routine tests at England's national performance centre then revealing that his action may breach the 15-degree limit for the straightening of the elbow.

Ex-England spinner Vic Marks said: "The timing is convenient, because England are getting stick for their selection.

"It nags at me how come this has just come out," added Marks, who played six Tests for England. "I don't like that it's come out after England have just gone for 759, with people rumbling about why he isn't here."

"I was stunned when I heard it," former Somerset captain Marks said on Test Match Special. "It just hasn't occurred to me that there was any problem at all. He looked to have a classic, orthodox action.

"However, it is hard to argue with the computer or camera."

Any problems with Leach's action would have had no bearing on the selection of the original touring party, but did prevent him from being called up as a replacement for Ansari after the third Test.

Dawson has gone on to make his debut in the fifth Test, where England conceded their highest total in Tests.

The Hampshire left-armer was the most economical of England's spinners in Chennai, taking 2-129 off 43 overs, while Moeen Ail returned figures of 1-190 off 41 overs and Adil Rashid claimed 1-153 off 29.4 overs.