A Melbourne police officer has been charged following a six month investigation by Victorian authorities, with a court today told the man offered sex for drugs.

The court also heard that the man, 33-year old former Leading Constable Huy Quach, had raped three women from 2004-2007, and was also alleged to have been involved in drug trafficking.

The six month investigation this week culminated in over 20 charges against the police officer, with those including four counts of rape and six of drug trafficking.

However the man's lawyer rejected the charges of drug trafficking, saying that the case against his client was weak.

The court also heard that Quach was a regular visitor of nightclubs, and had tried on several occasions to use drugs as a way of getting women to have sex with him.

Lawyers for the man also questioned the charges of rape, saying that at least two of the women had agreed to have sex with Quach.

The former officer remains in custody pending a further ruling, with Victorian authorities opposing his application for bail.