My life is a perfect example of an absolute waste': Andrew Chan's haunting letter to schoolchildren around the world, warning them about the dangers of drugs.

See the letter in pictures after the cut.

Chan's letter revealed how he became addicted to drugs at the age of 15
He also shared some of his deepest regrets and his agony behind bars
The letter was read out in a documentary made available to schools
The Bali Nine ringleader warns teens not to follow his footsteps and advises them to study hard and 'achieve more than I ever did'