Key admits ball-tampering

The England batsman was photographed using sandpaper on the ball, which he concedes was to aid reverse swing.

Key claims he was merely experimenting ahead of the season and would not attempt it in a first-class match, although he accepts he was "naive".

Key, 27, who has played 15 Tests, said: "My conscience is clear. I won't be going out and scratching the ball the way I have in this game in a first-class match but these games are used for practice and are a good opportunity to see where people are.

"The way the game is moving forward for bowlers nowadays is through reverse swing, so what we've tried to do throughout our pre-season nets was to get brand new balls, sandpaper one side, and let the boys practise bowling. It actually goes really well.

"Maybe I've been a bit naive but it didn't really occur to me that this might develop into a match-fixing scandal," he told The Guardian.

Any action seems unlikely as such friendlies do not come under the jurisdiction of the England and Wales Cricket Board and the game was umpired by local officials.

Kent have confirmed the game was regarded as "formalised practice" and will not be taking the matter further.

Nottinghamshire also have few complaints with their director of cricket Mick Newell saying: "It's not what you normally expect and we weren't aware of it. If I had noticed it I would have asked him what was going on.

"But I know Rob would not dream of doing it in a proper match and it was only a practice game."

Ball-tampering hit the headlines last summer when England's fourth Test against Pakistan at The Oval was abandoned after umpire Darrell Hair effectively accused the tourists of malpractice.