The trio have all won their appeals and will sign as Kolpak players
South Africans Andrew Hall, Justin Kemp and Johan van der Wath have been cleared to play in English county cricket after winning appeals.
The trio had initially been refused registration after competing in the unauthorised Indian Cricket League.
Hall's barrister Andrew Fitch-Holland told BBC Sport that an appeal against an "unlawful, unreasonable, capricious and discriminatory" ban was successful.
An England & Wales Cricket Board (ECB) spokesman declined to comment.
Hall and van der Wath are now free to play for Northants, with Kemp set to line up for Kent.
As the ICL is not sanctioned by the International Cricket Council, the ECB had warned earlier this year that any player who had taken part in the ICL and played domestic cricket in their home countries in the past 12 months would be unlikely to play in England this summer.
In April, the ECB rejected the applications from Hall, Kemp and van der Wath, along with West Indian Wavell Hinds - who had all played in the ICL - to sign for their counties as Kolpak players.
However, it did clear several other ICL players - such as former New Zealand pace bowler Shane Bond - to play for county sides.
Hinds had been lined up as a Kolpak player for Derbyshire - who have since signed him as an overseas player for part of the season.
The Kolpak ruling allows players from countries with associate trade agreements with the European Union - such as South Africa - to be treated as non-overseas players, although normally, only players no longer involved in international cricket are able to sign in this way.
THE KOLPAK RULING
Marus Kolpak was a Slovakian who won a restraint of trade case against the German Handball Federation at the European Court of Justice in 2003
Slovakia did not join the European Union until 2004 - but Kolpak won the right to not be considered as an overseas player, as his country had an associate agreement with the EU
The Kolpak ruling gives such players the same rights as an EU worker
As a result, many South Africans, Zimbabweans and West Indians have been able to play county cricket in England without a work permit - and not be classed as overseas players
Part of Hall's defence was that he joined the ICL in October of last year, before that legislation was in place.
"It is unfortunate the ECB refused the registration in the first place and that we had the time and expense of the appeals process," Fitch-Holland added.
"It (the result) vindicates our position."
Kemp could be available to play for Kent in Sunday's Friends Provident Trophy match against Sussex at Hove, subject to paperwork being completed.
Hall and van der Wath are still in South Africa but are expected to be back soon in action for Northants.
"We are delighted that both Andrew and Johan are now available for us for 2008," a Northants spokesman said.
"This strengthens our playing squad and enables us to push for honours in all competitions.
"We are looking forward to having both players with us as soon as possible."