Sydney private school students threatened with expulsion for plans to spit on homeless people, snort drugs in an end-of-year scavenger hunt

A private school in New South Wales has threatened students with expulsion if they take part in an end-of-year scavenger hunt described as "illegal, harmful, and disrespectful".

Sydney's Shore School discovered senior students had created the scavenger hunt called the "Triwizard Shorenament", where they would score points for completing tasks such as spitting on a homeless person, snorting a line of drugs, or getting arrested.

Other dares, which were brought to light after the list of tasks were posted on social media,  included group sex and vandalism.

"Unfortunately, the activities encouraged in the document featuring in media reporting today [Wednesday] are illegal, harmful and, in many cases, disrespectful towards members of the public and portray an arrogant sense of entitlement and an underlying attitude that the school finds deeply offensive," school principal Dr Timothy Petterson said in a message to parents.

"It is extremely disappointing to all of us that their thoughtless actions have cast a shadow not only over the considerable achievements of their classmates but the reputation of our school generally, which strives to be a respectful, inclusive and caring environment for all," said Dr Petterson, as reported by 7 News.

Other tasks included on the list included defecating on a train, trespass at Sydney's iconic Taronga Zoo, and "rip a cone" on the city's Harbour Bridge.

Dr Petterson said in a statement to 7 News the school body was appalled by the list.

"Any boy who does participate risks losing their place at Shore."

According to its website, Shore School places "a strong emphasis on character formation, challenging our students to be responsible citizens of integrity who seek to serve the wider community".

Local media outlets have described it as one of the most exclusive private schools in the country.