Gent, who appeared in U.K. TV series Torchwood and Being Human, has not been seen since 21 April (12), when he cancelled plans to meet friends in London.
His loved ones have now spoken out about his disappearance in a bid to locate the actor.
Gent's mother Alison tells London's Evening Standard, "We cling to the hope that someone somewhere might just recognise him and bring him back to his family who miss him so much."
Alison reveals her son had been under pressure after losing a call centre job which had supported him when he was not acting or auditioning, but adds: "He loved London so much and the buzz of the place, and he wanted to try to make it work there. This is really out of the blue."
His Being Human co-star Russell Tovey has also taken to his Twitter.com page to spread the word, telling his fans, "Just seen this in the paper...hope Richard contacts his family very soon."