The Natal Rich Boyz made the announcement on their Facebook account welcoming Sangweni back to his hometown.
"We would like to confirm the signing of Thamsanqa Sangweni, who will be joining the team until the end of the season. Welcome to the Natal Rich Boyz," the statement read.
The 29-year-old was released by Chippa United during the January transfer window after a not-so-successful spell in the Eastern Cape, then went to Maritzburg United to try his luck last month, which didn't work out.
Sangweni enjoyed his football at AmaZulu from 2009 to 2012 before challenging spells with Mamelodi Sundowns, Ajax Cape Town and Orlando Pirates that saw him being released to rejoin Chilli Boys before the beginning of the season.
Richards Bay FC are currently sitting in sixth position, four points behind second-placed Royal Eagles for the playoffs qualification position.
On Friday they face Ajax Cape Town at Athlone Stadium and it is believed that Sangweni has travelled with the squad.