The 29-year-old British sprinter, who served a two-year ban for doping, would hold a news conference on Monday, the club said on its website.
”Obviously we are well aware of Dwain’s background and we gave the whole situation a great deal of thought,” Castleford’s football manager, Michael Robinson, said.
”However, like people in our own sport, he has been punished and taken that punishment. That is now behind him and he is serious about trying to make the grade in rugby league.”
The club said Chambers would also be working with the squad on sprint training and would take part in community projects.
Chambers, who is barred from running for Britain in the Olympics because of BOA rules on drugs cheats, was reluctantly chosen for the British team at the world indoor championships in Valencia after winning the trials.
Londoner Chambers tested positive for the designer steroid THG in 2003 and was banned for two years. He later admitted he had been taking the banned substance for 18 months before he was caught.
Chambers, who was stripped of his 2002 European 100m gold medal, has also tried to forge a career in American football. — Reuters