The 26-year-old double amputee has been charged with the premeditated murder of his girlfriend Reeva Steenkamp, who was killed by the athlete when he fired four shots through a bathroom door in his home in Pretoria, South Africa on Valentine's Day.
"I've never seen Oscar with a gun, he has never mentioned guns and, apart from thinking it was likely he would own a firearm to protect himself at home, I have no knowledge of any history between Oscar and guns," Thomas told Inside Sport.
"We've been mates for seven years and we share an interest in cars and fast motorbikes. Oscar has told me that the way he unwinds is to take his bike out at night for a spin.
"The saddest thing is that a young woman has died and my heart goes out to her family."
Pistorius was granted bail following a four-day hearing at Pretoria Magistrates' Court last week.