Twala was released by Chiefs in June shortly after returning from an unproductive six-month loan spell at Maritzburg United.
The 28-year-old is also on the radar of former employers Chippa United.
"Free State Stars have made official contact," a source says.
"They are very interested to sign William Twala."
Meanwhile, Ea Lla Koto are still trying to secure the services of Thela Ngobeni from Mamelodi Sundowns and are close to making a call on trialist and fellow goalkeeper Dino Visser.
The Nedbank Cup champions recently added striker Eleazar Rodgers to their roster and agreed terms for the capture of former Platinum Stars forward Maboke Matlakala.