SYDNEY, March 29: One of Cricket Australia's biggest sponsors, fund manager Magellan, today tore up its contract with the governing body over the ball-tampering scandal that has rocked the game.

Almost simultaneously, sporting goods company ASICS announced it was ending its relationship with David Warner and Cameron Bancroft, two of the players at the heart of the cheating incident.

Magellan inked a three-year partnership in August 2017 as naming rights sponsor for Australia's domestic Tests in a deal estimated at the time to be worth Aus$$20 million. It began with the recent Ashes series against England.

This, it said, was based on "shared values and reputations of integrity, leadership, dedication and an unwavering customer-first culture".

"A conspiracy by the leadership of the Australian men's Test cricket team which broke the rules with a clear intention to gain an unfair advantage during the third Test in South Africa goes to the heart of integrity," said Magellan chief Hamish Douglass in a statement.

"Regrettably, these recent events are so inconsistent with our values that we are left with no option but to terminate our ongoing partnership with Cricket Australia.

"We were delighted with the recent Magellan Ashes Series sponsorship and it is with a heavy heart that we have to end our partnership in these circumstances."

The plot to tamper with the ball during Australia's third Test against South Africa in Cape Town last weekend has rattled the game and badly tarnished the careers of Warner, Bancroft and captain Steve Smith.

Warner and Smith have been banned from top-level cricket for a year while Bancroft got nine months.

Electronics giant LG on Wednesday dropped Warner as a brand ambassador and ASICS ended its relationship with the players in a tweet.

"As a result of last weekend's events in Cape Town involving members of the Australian men's cricket team and following the sanctions made by Cricket Australia, ASICS has terminated its sponsorship contracts with David Warner and Cameron Bancroft, effective immediately," it said.

Other team sponsors, including Qantas and Commonwealth Bank, have voiced their deep disappointment over the scandal but so far have taken no action.