A third Melbourne man has been charged with supplying the shotgun used in the fatal apartment siege in Brighton.

The 47-year-old Westmeadows man is the third alleged gun dealer to be charged following counter-terrorism raids across Melbourne’s north last week.

He was charged with multiple weapons offences including being an unlicensed gun dealer and being a prohibited person in possession of a firearm.

He appeared in Melbourne Magistrate’s Court on Tuesday.

A 25-year-old Gladstone Park man was arrested on Monday and charged with dealing a firearm without a licence, possessing a firearm as a prohibited person and other offences.

He is due to appear in Melbourne Magistrates Court on Wednesday.

Ascot Vale man Kane Dalrymple, 30, was also charged with being an unlicensed gun dealer, and he faced Melbourne Magistrates’ Court on Saturday.

The court heard Dalrymple allegedly made use of “coded” text messages to ply his trade, including code words such as “bicycle” and “two-seater”.

Police allege all three men are involved in the supply the weapons used by gunman Yacqub Khayre, who shot dead a hotel clerk during the siege in Brighton on June 5.

Khayre killed 36-year-old Nick Hao and took a woman escort hostage before opening fire at police, injuring three Special Operations Group officers.

The gunman died in a hail of police bullets.

Police later revealed Khayre had two shotguns at the siege, including the sawn-off shotgun used to fire at officers.

Counter-terrorism police stormed five properties in Ascot Vale, Gladstone Park, Glenroy, West Meadows and Reservoir on Friday.

-AAP