Alastair Cook has spoken of his “sadness” for cricket after Australia captain Steve Smith’s admission of premeditated ball-tampering in the Cape Town Test against South Africa.

Cook, the first England player to react publicly to the furore over Smith and Cameron Bancroft’s plot to change the condition of the ball at Newlands, has voiced a degree of empathy with the must-win pressures which face international captains.

But he has spelled out too that everyone must “play by the rules” at all times, for the good of his sport.

“It’s sad for cricket,” the former England captain told BBC’s Test Match Special.

“The guys who are in the limelight have a responsibility to play cricket in the right way.”

He cites England’s current plight against New Zealand, after being bowled out for just 58 on day one of the first Test, as a case in point.

“There are days when things don’t go your way – and the first day here in Auckland was a prime example of that – but there is always a way to get back into the game,” Cook added.

“We have to play by the rules.

“As captain, you are responsible for the other 10 guys and are the public figure for that.

“I’m sure Steve Smith is not in a very comfortable position – and in one sense you do feel for him, because I know what the pressure is like as captain of a country.

“You live and die by the sword.”

Smith said he was “incredibly sorry” for bringing the game “into disrepute” after team-mate Cameron Bancroft was caught rubbing a piece of tape, coated with dust from the pitch, on the ball while fielding on day three in Cape Town.

Former cricketers also reacted to Bancroft and Smith’s admission, with television pundit Shane Warne calling for answers.

The former Australia spinner told Sky Sports: “You can’t have that in the game. I don’t have any issue with anyone if they are sucking on a mint or chewing some gum – that’s just natural saliva. But if you use a foreign object then that has to be seriously looked at.”

Former England captain Michael Vaughan posted on Twitter: “Steve Smith,his Team & ALL the management will have to accept that whatever happens in their careers they will all be known for trying to CHEAT the game … #SAvAUS”

He later added: “The more you think about what has happened in Cape Town the more I realise the Leadership needs to be replaced … Positions are untenable … & I say that with the utmost respect for most of that group … #SAvAUS”

Smith’s predecessor as Australia skipper, Michael Clarke, was stunned to learn of the controversy.

He tweeted: “WHAT THE …….. HAVE I JUST WOKEN UP TO. Please tell me this is a bad dream.”