The largest Colombian "drug submarine" ever recorded was decommissioned in the Pacific Ocean, and three tons of cocaine were found on its board, AFP reports citing Colombia's navy.

The semi-submersible was intercepted on Tuesday en route to Central America, one of the most common drug smuggling routes to the US, the world's largest consumer of Colombian cocaine.

The detained crew members are all Colombian and claim to have been "forced by a drug trafficking organization" into taking the sub to Central America, the Navy said in a statement.