Casey Parker, with Colorado Springs Airport Operations, installs an amnesty box outside the security checkpoint at the airport in Colorado Springs. Picture: The Colorado Springs Gazette, Mark Reis

Los Angeles -

Airport officials in Colorado Springs, Colorado, on Wednesday helped confused marijuana users stay on the right side of the law by installing last-chance pot “amnesty boxes” where travellers could ditch the drugs before boarding planes.

The boxes are intended for travellers who may have brought marijuana into the airport by accident, local broadcaster KKTV reported.

While possession of a small amount of marijuana is not illegal in the state, passengers caught carrying it in the airport are subject to arrest and fines up to 2 500 dollars.

Those who drop in the trap-front metal containers, which are bolted to the ground, will not be prosecuted.

Denver International Airport will not install similar boxes, according to the report.

Colorado's liberalised marijuana law went into effect on January 1.

It allows people over 21 to buy marijuana for recreational use. Nonresidents may buy up to 7 grams, but are not allowed to leave the state with it. -Sapa-dpa