Nathan McSweeney has led from the front, hitting the winning runs as Australia A completed a seven-wicket victory over India A in Mackay after the day's play was marred by allegations of ball tampering.

India's players were told by umpire Shawn Craig the ball had been changed as it had been tampered with when players arrived into the middle.

"When you scratch it, we change the ball. No more discussion, let's play," Craig could be heard saying on the stump microphone.

India's wicketkeeper Ishan Kishan was then put on report by Craig for telling the umpire it was a "stupid decision".

"You will be on report for dissent. That is very inappropriate behaviour," Craig replied.

"Because of your actions we changed the ball."

Craig did not specify how he believed India had scratched the ball, and the tourists were not handed a five-run penalty.

Under the laws of the game, the umpires can request that a ball be replaced if they feel the original has been "unfairly changed".

Kishan is not part of India's Test squad for the Border-Gavaskar Trophy, which begins in Perth on November 22.

Fast bowler Prasidh Krishna, all-rounder Nitish Kumar and batsman Abhimanyu Easwaran are the only players in the India A side that form part of the Test squad.

There is no indication at this stage who umpires believe was responsible for the alleged tampering.

Once play resumed, the South Australia all-rounder hit an unbeaten 88 from 178 balls as part of a 141 partnership with Tasmania's Beau Webster (61 not out).

With other contenders Sam Konstas (0 and 16), Marcus Harris (17 and 36) and Cameron Bancroft (0 and 16) largely failing to impress, it was an innings that could yet be enough for the 25-year-old to earn a shock spot as opener in the first Test against India in Perth later this month.

The South Australia captain top-scored with a patient 39 runs in the first innings and repeated his efforts in the second, completing victory with a fine pull shot.

Having been christened as a leading contender by ABC Sport pundit Darren Lehman earlier this week, as well as former skipper Ricky Ponting, McSweeney underlined his credentials with another mature innings.

McSweeney averages 37.25 in first-class cricket with six centuries.

Ahead of this match, he scored 137 against Queensland in the One Day Cup after recording a half-century in the second innings of the Redbacks's Sheffield Shield victory.

He also scored 55 and an unbeaten 127 — his highest first-class score — against New South Wales in the season opener.

Australia A were always favourites to complete the victory in the first unofficial Test after India's paltry first innings effort of 107.

And, resuming at 3-139 at the start of day four, the unbeaten pair made short work of India's bowlers but not without some early drama, when the umpires requested a ball change.

AAP/ABC