Lyon sign Bok prop
The 36-year-old has been brought in to replace Georgian prop Zaza Navrozashvili, who picked up an injury in pre-season.
"I am very happy to be here, to resume training and especially the competition very soon. I met a great and very united team," said Botha.
"Everyone is very nice and friendly, I appreciate the infrastructure and I am delighted to be part of this team. I'm really excited to start this season with the Lyon.
"Lyon offered me the opportunity to race again after six months of inactivity and power, after eight years in Ireland.
"This prospect delights me enormously, I also heard many positive things about the Lyon through the various discussions I had with some players of the workforce. I find I incorporate an ambitious team that wants to count this year and I wanted to be part of this project.
"Above all, I want to be in shape quickly and remain so, I have to be strong on the field to help my teammates to defeat.
"The performance of each will get results every weekend to achieve a good place in Top 14."
Botha grew up in Durban and played for the Sharks from 2001 to 2008.
He played in the Currie Cup and Super Rugby for the Sharks. He played in all 13 Super Rugby matches in 2006 and was one cap shy of a half-century in the domestic Currie Cup.
Botha had been playing in Ireland since 2008 – first for Ulster 2008-2011 and then for Munster from 2011 to 2016.
He was capped 25 times for South Africa and scored one try during his international career 2006-2010.
In January the South African ruptured his anterior cruciate ligament against Stade Francais and it was then decided that he would leave at the end of the season.
