Grobbelaar, who became an individual medley specialist, announced his retirement from the sport yesterday.
"I am incredibly proud of my achievements in swimming," Grobbelaar said.
"While I didn’t end my career as I had once dreamed, I reflect with gratitude on the memories made, the incredible people I met, and the opportunities I embraced along the way.
"Representing two countries that hold a special place in my heart on the international stage has been the greatest honour of my life."
Grobbelaar grew up in South Africa and represented his home country at several international competitions, including the Commonwealth Games in 2018.
He later moved to New Zealand and swam for Neptune in Dunedin and was later selected as an Aquablack.
He made his Aquablack debut at the world aquatic championships in Fukuoka in 2023.
Previously, Grobbelaar represented New Zealand at the Fina world junior swimming championships in 2019 and the Fina world swimming championships (25m) in 2022.
