Bartlett's initial deal covered at least eight T20 Blast fixtures and Kent are awaiting confirmation as to whether he will be made available for that competition.

Simon Cook, Kent's director of cricket, said: "National boards are always going to protect their best assets, so it wasn't a shock when we received news from Cricket Australia that they would be withdrawing his NOC. This decision has potentially not ruled him out for the Vitality Blast, and we're continuing to discuss our options with Cricket Australia."

"We're really excited by the potential that Beyers has and what he can offer us this season," Cook said. "We looked very carefully at him earlier in the year but at that stage he hadn't played the required games to qualify as a viable overseas signing for us. He's a genuine allrounder who provides extra batting depth for us across all formats - a gap that we've looked to fill with our overseas players this year."

Swanepoel said: "I'm absolutely thrilled to join a historic county side such as Kent and to play in all formats of the English county game. I hope to learn a lot whilst I'm here amongst a very talented squad. I spoke to former Kent overseas players before I signed and they couldn't recommend Kent highly enough as a place to come and improve my game in English conditions."

Kent will start the season with Wes Agar as their only available overseas player, and face Somerset at Canterbury in the opening round of fixtures on Friday.