Melbourne: Cricket Australia (CA) said on Sunday they will conduct an investigation into a ball-tampering scandal during the third test against South Africa that has prompted calls for captain Steve Smith to step down.

‘From a Cricket Australia perspective we regard this as an extremely serious issue,’ CA chief executive James Sutherland told a news conference in Melbourne.

‘Activities on the field in Cape Town were neither in the spirit or the laws of the game. For us that’s extremely disappointing.’

Smith has admitted that the team’s ‘leadership group’ orchestrated a plan to use sticky tape to pick up hard granules from the pitch and rub these against the ball to try to alter its condition and get it to swing.

Opening batsman Cameron Bancroft, 25, the most junior member in the side, was the player tasked with implementing the plan and he has been charged by the International Cricket Council.