South African Rilee Rossouw says he was "abused" by countryman Dean Elgar about his decision to turn his back on the Proteas, which spurred the 27-year-old on to a match-winning century in an English county match on Thursday.

Rossouw controversially joined English county side Hampshire on a three-year deal in January, effectively ending his international career with the Proteas.

Rossouw signed with Hampshire earlier this year // Getty

The decision to take a big-money Kolpak offer was not well received in his homeland so it's perhaps unsurprisingly that Elgar had a few choice words for his former teammate when his Somerset side faced Rossouw and Hampshire in the one-day cup this week.

But Rossouw says Elgar's sledging when he first arrived at the crease only motivated him to blast a match-winning 156 from 113 balls as Hampshire won by four wickets.

"It was like a switch went on and I started middling everything from there, so thanks Deano for that 156," Rossouw told BBC Radio.

"I stayed in my bubble and didn't let the chirps or the bowlers get to me.

"I'm not going to say what was said, but it was something to do with the pound (money). It was a switch and from there, I just started hitting boundaries."

Elgar had earlier been involved in a comical run out during Somerset's innings.

In January, Rossouw was publically slammed by Proteas coach Russell Domingo as well as Cricket South Africa boss Haroon Lorgat over his decision to join paceman Kyle Abbott in signing a big-money Kolpak deal.

"I haven't heard from Rilee since we left Australia to be honest," Domingo said of the Test tour of Australia a few months earlier, where Rossouw had been selected as a back-up batsman.

"Some of us have tried to get hold of him, and this is the truth, we got an email from him off his iPhone telling us he's signed Kolpak. He spelt my name wrong for starters. He wrote one L instead of two. That's where we are.

"I am bitterly disappointed in him. That's the bottom truth.

"He toured Australia as the back-up Test batsman. He was the next batsman in."

Lorgat pointed to the "immeasurable amounts" of resources his organisation had invested in players like Rossouw and Abbott.

"It is a disappointing day not just for South African cricket but also for international cricket as these players have given up their opportunity to be seen in action on the international circuit," Lorgat said.

"From CSA's perspective it is a loss as we invest immeasurable amounts which include premium time, finance, technical, high performance coaching followed by development tours and providing general player welfare over a long period of time.

Rossouw ton takes Proteas to 8-327

"By way of example, Rilee has spent a lengthy period on the injury list while we spared no expense in providing him with the best medical support."

South Africans are able to play in England under the Kolpak ruling, a 2003 European Court of Justice decision, but uncertainty about the future of the ruling following the United Kingdom's referendum in favour of leaving the European Union is seen as a factor in the rapidly increasing exodus of talent out of South Africa.

Abbott and Rossouw were the biggest names to move to England after Stiaan van Zyl (Sussex), Simon Harmer (Essex) and Hardus Viljoen (Leicestershire) all chose county cricket over representing their country.

All of these players have been signed as Kolpak players, making them ineligible to play for the Proteas for the duration of their county contracts.

The players were lured to England by far more lucrative deals than they'd get in South Africa; for example, The Guardian reported in December that Van Zyl's deal with Sussex is worth around three times what he would earn for his South African domestic side, the Cobras.