A coroner is questioning how a man so intoxicated he later died was able to slip through airport security and onto two flights.
Suman Dahya, of Paraparaumu north of Wellington, died at his home on December 30, 2011, after ingesting a lethal concoction of methadone and diazepam.
The 53-year-old died of the lethal overdose just hours after flying home from a holiday to India.
He was found by security slumped in Wellington Airport and started coughing up blood after being taken home by his wife.
Prior to being found in this state, Dahya had managed to board his flight in India, get through customs in Auckland and board another flight to Wellington.
Coroner Ian Smith said he was surprised the man was allowed onto planes, both in India and later while transferring to a domestic flight in Auckland.
"I find it quite surprising that this man appears to have flown on an international flight ... when he was clearly under the influence of a concoction of drugs."
Responding to the coroner's concerns, Auckland Airport aviation security said unless Dahya had set off the metal detector or smelt of alcohol it was unlikely security would have noticed him.
Dahya had a history of substance abuse and was undergoing drug treatment at the time of his death.