A North Korean ship caught trying to move undeclared Cuban weapons through the Panama Canal has left to return to Cuba.
The Chong Chon Gang freighter departed from the Panamanian port of Colon on Saturday with a crew of 32 on its way back to Cuba, Panama's foreign ministry said in a statement.
The ship got the green light last week to leave Panama after Pyongyang paid a fine of nearly $US700,000 ($A783,000).
In July, the ship was stopped on suspicion of carrying drugs as it tried to enter the canal, the busy waterway linking the Caribbean and Pacific.
A search by Panamanian authorities uncovered 25 containers of Cuban military hardware, including two Soviet-era MiG-21 aircraft, air defence systems, missiles and command and control vehicles.
The containers were concealed under more than 200,000 sacks of sugar.
Both Havana and Pyongyang said the weapons were obsolete Cuban arms being shipped to North Korea for refurbishment under a legitimate contract.
But neither country explained why the shipment was hidden.
Last month Panamanian authorities dropped charges against 32 of the 35 North Korean crew members.
The remaining three - the vessel's captain, first officer and political secretary - have remained in custody in Panama, facing trial on arms trafficking charges.
