A controversial billboard near the Indianapolis Motor Speedway has been slammed by Kiwi driver Scott McLaughlin.

Three billboards with the phrase “Winners Don’t Drink Milk” have been erected near the circuit ahead of Monday’s Indianapolis 500 race, where the winner traditionally toasts their victory with a pint of milk.

A group called the Physicians Committee for Responsible Medicine is responsible for the campaign, claiming cow’s milk can increase the risk of prostate and breast cancers.

They’ve written to the boss of the Indianapolis Motor Speedway, urging them to present the winner with a bottle of plant-based milk or water instead.

McLaughlin tweeted saying to give him two bottles of milk if he wins now.

“This hits home for me. My mum was a dairy farmer with her family. This is a business for some people. I will always support the milk industry,” he said.

The options of milk varieties for drivers are slim - either whole, 2 per cent or fat-free milk.

McLaughlin qualified in 14th place for his third attempt at winning the famous race. His best finish to date was 20th in 2020.

Fellow Kiwi Scott Dixon qualified sixth. He is aiming to win for the second time at the Brick Yard following his 2008 victory. Dixon’s teammate Alex Palou will start on pole.

Scott Dixon drinks the ceremonial winner's milk after victory at the 2008 Indy500. Photo /Getty