One in three people have experienced sexual harassment at work in the past five years, according to authoritative new research by the Australian Human Rights Commission – a significant increase in the prevalence rate recorded by previous surveys.

The study to be released in Canberra on Wednesday finds 71% of Australians have been sexually harassed at some point in their lifetimes, with more than four in five (85%) of Australian women and more than half (56%) of Australian men over the age of 15 experiencing the behaviour.

The rates of sexual harassment were highest among people aged 18–29, with three in four people (75%) in this age group having experienced sexual harassment during their lifetimes.

The study suggests people identifying as gay, lesbian, bisexual, pansexual, queer, asexual, aromantic, undecided, not sure, questioning or other are more likely than people who identify as straight or heterosexual to have experienced workplace sexual harassment in the past five years (52% and 31% respectively).

The rates were also higher for Indigenous people and people with disabilities.

The research, to be unveiled at the National Press Club by the sex discrimination commissioner, Kate Jenkins, finds perpetrators are overwhelmingly male. Almost two-thirds (64%) of workplace sexual harassment in the past five years was carried out by a single perpetrator, and the perpetrators were most often a co-worker at the same level as the victim.

But despite the apparent ubiquity of the behaviour, very few people, only 17%, make complaints. A majority of victims complain to their direct supervisor.

But many complainants paid a high price for speaking up. Almost one in five people who made a formal report were labelled as a troublemaker (19%), were ostracised, victimised or ignored by colleagues (18%) or quit their job (17%).

In one in five cases (19%) the formal report or complaint brought no consequences for the perpetrator. The most common outcome of reports or complaints was a formal warning to the perpetrator (30% of cases).

Almost half (45%) of people who made a formal report said that no changes occurred at their organisation as a result of the complaint, and women making formal complaints fared worse than their male counterparts.

The most common reasons given for not reporting their experience with workplace sexual harassment were that people would think it was an overreaction (49%) and it was easier to keep quiet (45%).

The survey, the fourth of its type, also indicates the reporting of workplace sexual harassment has decreased over the life of the research. In 2003, 32% of people who had experienced reported the behaviour or made a complaint, compared with 16% of people in 2008, 20% of people in 2012 and 17% of people in 2018.

The 2018 survey was conducted using a much larger sample than in previous years, surveying 10,272 people in total.

Jenkins writes in a foreword to the new report that the data confirms in the vast majority of cases, sexual harassment is perpetrated by a man “and in many cases it is ongoing over an extended period”.

“Half of victims have experienced similar harassment before, and a substantial proportion experience negative consequences as a result, such as impacts on mental health or stress,” she said.

Jenkins said the survey found harassment rates were particularly high in the information, media and telecommunications industries, and it was disturbing that the rate of complaints was so low.

She said employers had a significant role to play in preventing the behaviour from occurring and in responding appropriately when complaints were made.

Jenkins said the rates of harassment recorded in the fourth national survey undertaken by the commission were “a marked increase in the prevalence rate recorded by previous surveys”.

“We cannot be certain if this is due to an increase in sexually harassing behaviours, or to greater awareness of the types of behaviours that constitute sexual harassment, or to other factors,” she said.

“What we are certain of is that this is a problem that affects millions of Australians and we, collectively, have a big job ahead to tackle the problem.”

The findings of the survey will feed into a national inquiry into sexual harassment in Australian workplaces to be spearheaded by the commission, partly in response to shocking revelations from the #MeToo movement.

The minister for women, Kelly O’Dwyer, confirmed in June that the commonwealth would contribute $500,000 to that inquiry.

Jenkins said the findings of the survey “compel us to take action to change the underlying social norms and inequalities that contribute to sexual harassment, to change workplace cultures that do little to address sexual harassment and to respond appropriately when sexual harassment occurs”.

“Our goal must be to ensure all people work in an environment that is safe and non-threatening.”

O’Dwyer said the national inquiry would contribute to the task of employers reducing the prevalence of sexual harassment in the workplace “and ensure, where it does occur, it is dealt with sensitively and appropriately”.

“Women should feel safe at work, and in every other aspect of their lives.”