Mexican authorities have seized a homemade cannon along with cartridges, chargers and more than 800 kilograms of marijuana in the Mexican border town of Agua Prieta, Sonora.

The Attorney-General's office (PGR) said the device used compressed air to fire packages of narcotics from Mexico into the US.

The joint operation between Mexico's Ministry of National Defence (SEDENA) and the CIA on November 9 recovered 203 packages of marijuana weighing 825 kilograms, 1,965 cartridges of different calibres, 26 charges and the cannon from a van.

An officer shows the cylindrical package of drugs fitting in the tube of the cannon. ( Supplied: PGR )

Mexican media reported the cannon was designed so it could be fired through the van's sunroof.

The items are being kept in the public prosecutor's office while the investigation continues.