If Singaporean authorities order the caning of a Perth man accused of swearing on a plane, it should be considered torture, Amnesty International says.
Maritime worker Bruce Griffiths, 47, is being detained in Singapore after he was arrested on a Tiger Airways flight from Perth on January 4.
Australian consular officials are assisting Mr Griffiths, who has had his passport seized and is facing accusations under Singapore's strict outrage of modesty laws.
Mr Griffiths is said to have become involved in a swearing match with another male passenger whose sleep he disturbed while allowing a female passenger out of her seat.
The offence - which legislates against “use of criminal force to any person, intending to outrage or knowing it to be likely that he will thereby outrage the modesty of that person” - carries penalties of two years' jail, a fine, caning or a combination of each.
Amnesty International spokesman Edwyn Shiell said the level of punishment for the offence was outrageous.
“Judicial caning is quite a common practice in countries like Malaysia, Singapore and Indonesia, and routinely is carried out against asylum seekers, migrant workers and women in particular,“ Mr Shiell said.
“We regard this punishment as cruel, inhumane and degrading punishment, and Singapore's use of this punishment is contrary to the global ban on torture.
“We consider it a form of torture.”
Tiger Airways confirmed there was an incident on the flight, and said it would not compromise on its zero-tolerance policy of bad behaviour on its carriers.
“Tiger Airways has a zero tolerance policy towards inappropriate behaviour on board our aircraft,” a spokeswoman said.
“Safety and security of staff and passengers underpins the operation at all times and is something we will not compromise.”
Mr Shiell said the image of bloodied and battered recipients of the cane in recent years should not be underestimated.
Footage that had come out of Malaysia in recent years was “gruelling“, Mr Shiell said.
“It is quite gruesome, and certainly a very serious punishment.”
Recent cases of foreigners being caned in Singapore include Swiss national Oliver Fricker, who was sentenced to five months' jail and three strokes of the cane in 2010, after pleading guilty to cutting through a Changi train depot fence with an accomplice and spray painting two metro train carriages.
In the same year, former Florida State University NFL star Kamari Charlton was sentenced to the cane after he overstayed his tourist visa in Singapore and was charged with a phone scam against an Australian man.
American Michael Fay, 18, was sentenced to four cane strokes in 1994 for theft and vandalism.
The caning was carried out despite pleas for leniency from President Bill Clinton and US Embassy officials.