The Mexican liquor is made with juice from the cactus-like agave plant

A Berlin barman has gone on trial accused of having served a 16-year-old boy 45 tequila shots, which killed him.

The barman is charged with having "fatally injured" the boy in his bar in February 2007. The barman has admitted responsibility, German media report.

The 28-year-old barman, identified only as Aytac G, allegedly had a drinking bet with the schoolboy, but poured mostly water for himself.

The boy fell into a coma with alcohol poisoning, and died four weeks later.

The case triggered outrage in Germany and a heated debate about binge drinking by teenagers.

Two men aged 18 and 21, who encouraged the 16-year-old to down the tequilas, were sentenced in November to complete a compulsory social training course.

Prosecutors accuse the barman of having also served alcohol illegally to youths on 173 occasions in 2005-2007.