The death of University of Newcastle Professor Kypros Kypri has been met with shock and sadness, amid tributes to his legacy and "sharp intellect".
Friends and colleagues said Professor Kypri died in a cycling accident in Dunedin in New Zealand on Saturday.
A New Zealand Police statement on the incident said "no other vehicles were involved".
"Emergency services attended but sadly, the cyclist died at the scene. The Serious Crash Unit attended and enquiries are under way to determine the circumstances of the crash."
Professor Kypri, a behavioural scientist, was an expert in epidemiology and prevention of alcohol-related injury and disease.
Professor Frances Kay-Lambkin, Hunter Medical Research Institute [HMRI] director and chief executive, said his legacy was "one of fearless integrity combined with a sharp intellect".
"The HMRI family is shocked and saddened by the sudden loss of Professor Kypri - or Kyp, as we knew him," Professor Kay-Lambkin said.
"We will miss our conversations with him."
She said he was "an ethical and curious man whose convictions around the best ways to support people experiencing substance addiction will leave a lasting impact on both public policy and the Newcastle community".
"We are heartbroken for his lovely family as they grieve the loss of Kyp, especially in the context of the recent loss of their dear Luke. You will always be part of the HMRI family, and we are here to support you as you need us."
Luke Kypri died at age 19 in February last year in Dunedin Hospital, after being diagnosed with a rare and life-threatening auto-immune condition.
Professor Kypri was a prominent voice in the lockout laws debate. His research into alcohol and violence was instrumental in the NSW government's adoption of the "Newcastle solution" in 2008 to reduce night-time violence in the city.
He won the Sax Institute's Research Action Award in 2017 for his work analysing the effects of the city's lockout laws on assaults in the CBD.
Dr Ben Ewald, a colleague who previously sat next to Professor Kypri at HMRI, said his friend's death was "terrible news".
"It's a great loss to Newcastle and Australia. He was a great academic and a champion for academic integrity," Dr Ewald said.
Dr Ewald said "his academic area was alcohol policy".
"He researched the effect of the alcohol marketing industry and the push to increase alcohol consumption by advertising.
"He did important work on the ways in which business practices lead to poor health outcomes."
Dr Ewald said he had "done a few cycling trips with Kyp".
"We did a great bike tour around Mount Yengo a few years back. He was always up for a cycle adventure."
Newcastle community advocate Dr Tony Brown worked with Professor Kypri on alcohol harm prevention.
"Kyp was an international scientific icon in evidence-based alcohol harm reduction research," Dr Brown said.
"He was a great guy with a humble touch, an outstanding academic and very sympathetic to worthy causes. He had a willingness to support the underdog."
Professor Kypri, who had a "passion for cycling", once cycled from Newcastle to northern Sydney for a morning meeting.fHMRI
"We were stunned when he entered the cafe in his Lycra with his bike," Dr Brown said.
"He was a bright light in terms of the way the community and government should adopt an evidence- and science-based approach."
Dr Brown said it was a "terrible tragedy" to have lost Professor Kypri.
"He loved his family and Newcastle," he said.
