Hampshire have re-signed Kyle Abbott and also brought in fellow South African Rilee Rossouw.
Abbott, who returns to the Ageas Bowl following a successful spell with the club in 2014, has signed a four-year deal under the so-called Kolpak registration process.
Fellow countryman and top-order batsman Rossouw has also committed his long-term future to Hampshire, having signed a three-year contract – again as a Kolpak registered player.
Hampshire Director of Cricket, Giles White, said: ‘We know Kyle well from his previous stint with us and Rilee comes with an excellent reputation.
‘Both are players of high quality and their commitment to long-term contracts is a major boost to the Hampshire playing squad ahead of the 2017 season.
‘We are confident that having them around will have a big influence both on and off the field.
‘We are excited about their arrival and look forward to welcoming them and their families to the club.’
Twenty-nine-year-old seamer Abbot made a positive impression during his time with Hampshire two years ago, claiming 36 first-class wickets at an average of just 20.33 during his season-long stay.
The right-armer has also featured prominently for South Africa on the international stage since making his debut in 2013, taking 99 wickets in just 59 matches across all formats, including outstanding figures of six for 77 against Australia in November 2016.
Rossouw has also impressed at international level since making his debut in 2014, representing South Africa in 51 limited-overs fixtures.
The left-hander has totalled more than 1500 runs during that time, including an outstanding innings of 122 in his last international appearance in October – a knock which helped guide his side to an ODI series whitewash over Australia.