A video has emerged showing two US border officers apparently encouraging a teenager to drink liquid methamphetamine shortly before his death.

The footage, obtained by Australia's ABC News and filmed in the US in 2013, appears to show two US Customs and Border Protection officers smiling to each other as they seemingly encourage Cruz Velazquez to drink from a bottle containing yellow liquid.

The 16-year-old died two hours later. The substance turned out to be a concentrated liquefied methamphetamine.

The two officers, Valerie Baird and Adrian Perallon, who both deny encouraging Velazquez to drink from the bottle, have escaped disciplinary action and currently remain in service.

However, the video shows Cruz taking four sips from the bottle after being asked to do so by the two. The teenager was initially stopped after a dog detected the presence of drugs and admitted the liquid contained in the bottle was indeed a chemical, before beginning to complain about feeling sick shortly afterward.

Cruz was subsequently taken to the Sharp Chula Vista Medical Center in Chula Vista, California, but died two hours after arriving at the facility.

Cruz's family have launched a lawsuit against the two officers, alleging their actions led to the death of the high-school student.

Gene Iredale, the family's attorney, said the surveillance video proved Baird and Perallon took pleasure by forcing Cruz to drink the liquid.

"What you see, I think, is a basic lack of compassion and decency toward a 16-year-old boy," he was quoted as saying by ABC News.

"Almost a delight that you would see in children who just pull the wings off flies slowly, a smile when he's being asked to drink something and being put in this position."