Havana, Cuba (CNN) -- Cuban weapons found in July aboard a North Korean ship trying to cross the Panama Canal violated United Nations weapons sanctions, Panamanian officials said, citing an unpublished U.N. report on the incident.
Cuban officials said Thursday that they had no comment on the Panamanian allegations.
In July, Cuba's foreign ministry issued a statement that said the undeclared shipment discovered aboard the ship consisted of obsolete weapons being sent to North Korea for repairs before being returned to Cuba.
But Panamanian officials have said that under 10,000 tons of Cuban sugar, they found operational weaponry, including MiG fighter jets, anti-aircraft systems and explosives.
"The Cuban weapons on the North Korean ship undeniably violated the U.N. weapons embargo," said a statement issued Wednesday by Panama's Ministry of Public Security, citing a preliminary report by U.N. weapons inspectors who inspected the ship.
Despite Cuba's assertions that the weapons were being sent for repairs, the shipment may have been intended to bolster North Korea's own defenses.
"North Korea is very interested in maintaining its MiG-21 fleet," said James Hardy, Asia-Pacific editor for Jane's Defence Weekly. "It may be a 50-year-old plane, but it's very fast and capable in a dogfight."
Still, Hardy said, if the shipment was part of an illegal arms deal, it remains to be seen what further sanctions Cuba or North Korea could face.
"The U.N. sanctions are very strict," he said. "But the consequences are not clear."
While authorities have not said what will become of the Cuban weapons, the North Korean crew may finally be heading home.
Panamanian authorities met Wednesday with North Korean diplomats and said they agreed to begin the process of repatriating the 35-member North Korean crew, who have been held in Panama after initially trying to prevent authorities from searching the ship.
That ship, the Chong Chon Gang, could also be returned to North Korea after repairs are made. According to the Panamanian statement, the crew rendered the ship inoperable during the struggle to keep customs authorities from boarding it.
Although secret shipments of arms between North Korea and Cuba were not previously well-known, they apparently have taken place for decades.
In July, former President Fidel Castro wrote that in the 1980s, North Korea sent Cuba 100,000 AK-47 rifles after the Soviet Union denied the island military aid that could be used to repel a feared U.S. invasion.
"They did not charge us a cent," Castro wrote of the North Korean shipments.