The 23-year-old spent one-year in prison out of the two years handed him after being found guilty of sexual assault on his former wife.
He was released for putting up a good behaviour and has been training with Kotoko since Tuesday in a bid to re-launch his career since he is now a free agent after his contract with Gefle was mutually terminated.
"It's true we invited Kwame Bonsu to train with us and he has been impressive so far," Duku told Goal.
"He is a free agent so the club will be ready to sign him for next season when the normalisation committee complete their work and football returns. However, that decision will be taken based on the recommendation of the coach and his backroom staff.
"We are aware of his quality but the coach must first recommend that he is needed and further convince the club's top hierarchy why he must be signed ahead of other players," he added.
Bonsu began his career with Anokye Stars in Kumasi and moved to Heart of Lions before joining Mjallby in Sweden in 2014.