Illegal forestry in particular was responsible for losses averaging some 152 million euros a year, the National Anti-Corruption Commission report said, quoting an investigation by environmental groups including Greenpeace and Forest Monitor.
Cameroon is perceived as one of the most corrupt countries in the world, according to the watchdog Transparency International.
Under pressure from donor countries, the government has launched a crackdown on corruption which has resulted in heavy prison terms for former minister and heads of state entreprises.
Even so, the report said that in the opinion of experts and other informed observers, reforms and sanctions have not had a significant impact.
Officially the government strategy is for Cameroon to be a country of integrity by 2015, "with economic growth based on work well done, shared out in an equitable fashion."
The strategy targets 10 priority sectors, including the public investment budget, contracts, finance and forestry.
Under a 1996 law that has yet to be implemented senior state officials are meant to disclose their assets fully.