The tall defender has been without a club since leaving Bakgaga at the end of last season and Phunya Sele Sele have moved to bring the free agent in to bolster their defence.
Celtic lost Alfred Ndengane to Orlando Pirates in the first half of the season, while Lorenzo Gordinho returned to Kaizer Chiefs at the end of December following the expiration of his loan deal.
So Celtic have been in need of replacements and Mahashe will no doubt add the value they need at the back, and upfront too, because he can contribute with goals.
Mahashe has signed a deal for a season-and-a-half with Phunya Sele Sele, who are currently in fifth place on the Absa Premiership standings.
The 30-year-old has been included in the squad of 22 to travel to Polokwane for Sunday's Absa Premiership match against his former side Baroka at Peter Mokaba Stadium (15h30).
He would no doubt be happy to make his debut against his former employers.