An attempted mass poisoning in 1981 has been discovered alongside more than 110 newly unearthed Indigenous massacre sites identified by academics.

The University of Newcastle’s Colonial Frontier Massacres Digital Map Project’s final findings added a further 113 sites, bringing the tally to 415 sites where at least six people were killed in anti-Indigenous attacks carried out since colonisation began.

The research has also found almost half the massacres of Aboriginal people were by police or other government forces.

Most of the 113 additional sites were in Western Australia and the Northern Territory.

Dr Robyn Smith, who has worked on the project, told the National Indigenous Times an attempted poisoning massacre in 1981 killed two Aboriginal people, and put 14 others in hospital.

“A bottle of port or sherry was deliberately left on the grounds of John Flynn church, in Alice Springs, a known drinking place,” she said.

“A group of 16 people started to drink this bottle – two died and 14 were admitted to hospital.

“Quite a team of detectives worked on that, but they were looking for fingerprints on a bottle that had been handled by so many people.

“What I find extraordinary about that is that it is possible that whoever did that is still alive and walking around today.”

Dr Smith said a coronial inquest into the incident found the victims were murdered, and the it was believed strychnine was used.

“no one wants to admit that this is what happened as part of the colonisation process” – Robyn Smith

The poisoning was not placed on the map as it did not meet the threshold for a massacre of killing six or more people, but plenty more have been added.

Dr Smith said a “code of silence” maintained by perpetrators and wider society had protected the killers.

“It did happen certainly on Elsey Station. Jeannie Gunn’s book originally included a chapter called n***** hunt or going on a n***** hunt that was removed from the book in 1925 when it went into schools,” she said.

“In that chapter she refers to it couched in terms of the stockmen rounding out her education, taking her on a hunt.

“She talks about two parties meeting at Red Lily Lagoon, a site of frequent massacres – this is not fiction.

“The Victoria River District of the Northern Territory, which abuts the Kimberley region, was a very brutal area.”

Dr Smith noted more recent massacres were more difficult to uncover as efforts were made to conceal the crime.

She said contemporary newspapers held in the national library often included references to massacres, using euphemisms such as ‘a police party has gone out to teach them a severe lesson’ or ‘a party of volunteers has gone out and will, we trust, teach them a lesson’.

“It is possible that whoever did that is still alive and walking around today” – Robyn Smith

She also noted letters to editors and, very rarely, personal correspondence, made references to massacres.

Official records and police reports were also used to document massacres, including a poisoned horse meat incident in Arnhem land between 1903-08 at Arafura Station, where many Yolngu people died.

Cases of poisoned damper and poisoned chewing tobacco were also uncovered, as well as an attempted poisoning at Mainoru Station near Katherine during World War Two, where a sacked manager “tried to wipe out the work force” at the station.

Dr Smith said ongoing attempts to deny and downplay colonial violence against Aboriginal people reinforced denial of an inconvenient truth.

“It’s entirely unpleasant; no one wants to admit that this is what happened as part of the colonisation process,” she said.

“Aboriginal people know all about it because it is in their oral history, their family and community history.

“Truth was my motivation… There is no way in the world we have documented every massacre in Australia’s colonial history.”

In total the project has found between 11,000 and 14,000 Aboriginal people died in massacres, compared with 399 to 440 colonialists.