The assault rifles and pistols arrived in Haiti stashed in two cardboard boxes, nestled among packages of food and clothes, on a cargo ship stacked with rust-red shipping containers.

They had come from the US, which one expert describes as a “supermarket” feeding an arms race among gangs that have brought chaos to the Caribbean island nation.

An investigation by the BBC World Service and BBC Verify traced the two boxes’ journey, showing how weapons from the US reach Haiti. It reveals a chain of lax laws, absent checks and suspected corruption used by traffickers to bypass a UN embargo.