Five are boxers and three weightlifters.
Cameroon say eight of their 42-strong Commonwealth Games team are missing, with one boxer's failure to appear at an event gifting his Canadian rival a medal.
Three athletes left the village on the night of April 8, two others were declared missing on April 9, and three more had left their rooms on the night of April 10.
Mr Nso said team officials had notified Australian police.
The young Mitharval, who has also a bronze in the 10m air pistol event two days ago, shot 201.1 to finish third in the eight-man finals at Belmont Shooting Centre.
Reacting to the budding home-based athletes selected to represent Nigeria at the Games, Fasuba said it was a good idea to expose them.
"It is obviously disappointing that some of the athletes who have come didn't compete when scheduled to compete", he said at a press conference Wednesday.
Indeed, this is not the first time that Australia has had such problems as more than 100 athletes overstayed their visas having gained entry to the country via their participation at the 2000 Olympics in Sydney.
"While the athletes are free to travel within Australia, we share the concern of the Cameroon Commonwealth Games Association of the safety, welfare and whereabouts of the athletes". I believe they will be working on baton exchange although I would have preferred if it was done longer.
"Nobody said anything, they did not give any condition, they just left". There are a few areas we have noticed which require improvement and we have addressed them within the team.
"How can you go back without people you came here with?" he asked. I am very happy to contribute something for the country and my teammates.
MC Mary Kom is on course to claim India's first Commonwealth Games gold in women's boxing after her defeat of Sri Lanka's Anusha Dilrukshi Koddithuwak in the 48 kg bout.
This is the second time since 2012 that Cameroonian athletes have gone missing at an worldwide competition.
Members of the Cameroon team arrive during the opening ceremony. Two Cameroonian weightlifters Francois Etoundi and Simplice Ribouem were granted refugee status, competing for Team Australia this year.
"We would appreciate them sticking within the law, enjoying themselves, but sticking within the law", organising committee boss Peter Beattie told reporters.