Almost one in two workers end up in a sexual relationship with a colleague.

The problems escalate when there is a power imbalance such as the one between former Seven West Media executive assistant Amber Harrison and her then boss, Tim Worner.

In cases of sexual harassment, there are clear guidelines for HR managers.

But relationships such as the one between Worner and Harrison "fall between the cracks of HR", says Angela Knox, associate professor of work and organisational studies at the University of Sydney business school.

"It has simply been a personal relationship that was inappropriate on a personal and professional basis, but in a workplace sense was not illegal," she says.

"In a professional sense what you should do if something like that was to occur is to declare the relationship and ensure the reporting lines change so that the subordinate is not reporting to their superior who they are in a personal relationship with.

"If things go sour, there is less impact because it is not their ex-sexual partner who is overseeing them, it is someone independent of that relationship."

Any romantic relationship needs to be taken outside the management hierarchy. Where there is an imbalance in the power relationship, this works to protect both the boss and a subordinate employee.

Peter Wilson, chairman of the Australian Human Resources Institute says the role of HR is to step around the two parties and report to a higher authority, such as the board, if senior managers are involved.

A human resources department should raise the issue with the chairman because it has potential to affect the culture of an organisation. An independent review at arms' length from management is needed to resolve an issue involving senior managers.

All employees, whether an executive assistant or a executive manager, have equal rights to be treated fairly.

That the consensual affair between Worner and Harrison involved an obvious power imbalance is crucial.

Harrison claims Worner charged the company for travel expenses for his trips to her home for sex. She says he also asked her to come to the Australian Open tennis championship in Melbourne in 2014, aware that she put the cost of the flights, accommodation and room service on the company credit card. She also claims the pair used cocaine during their sexual encounters during work functions in 2013.

Alleged drug use at work events and inappropriate use of credit cards should fall within a company's formal HR policies with specific reporting and investigation procedures to be followed, Knox says.

Wilson's institute was involved in a global study that has found up to 47 per cent of people have an intimate sexual relationship with a co-worker at some time in their career. While not unlawful, it raises questions.

Wilson says they are: "Does it involve the resources of the company to support that relationship? And what are the implications for others in the workplace who may fear their fair treatment could be affected?"

The institute advises co-workers to declare a romantic relationship publicly sooner rather than later. Lingering gazes and telling body language can often give them away.

"Their co-workers are very good detectives ... and people start to talk," Wilson says.

"People are very intuitive. So it is better if you're involved in one to say, 'We are in a relationship.'

"If it involves a boss and a subordinate, then usually it is best in the interests of other people in that work group if there is a separation."

Otherwise, co-workers could feel disadvantaged by pillow talk.

"HR's job is to act in the overall interests of the people in the company, fairly and without favour," Wilson says.

"Unfortunately there are cases where the power structure is involved and you can get defensive reactions to support the boss, most generally a male and the position of the female, who is generally a subordinate, can be at risk."

The tendency for human resources managers to side with the boss and get rid of people who make the manager uncomfortable "is old game, not new game".

It still happens. But Wilson says many organisations have human resources teams with the courage and independence to do the right thing.

Approaches to HR have been improving out of necessity to help businesses in competitive industries to attract the best talent. Employees vote with their feet if they are not treated fairly.

There is less of a tendency to walk away within the heavily disrupted media industry, which has been shedding jobs.

"That's where people get trapped and where bullying and sexual harassment can thrive. That's what the data tells me," Wilson says.

The institute published a set of HR examples after Kristy Fraser-Kirk launched a $37 million sexual harassment lawsuit against David Jones and its former chief executive Mark McInnes in 2010. David Jones reported a settlement amount of $850,000 to the stock exchange, inclusive of legal costs and expenses.

Blokey work cultures can often become sexualised. The media industry has traditionally been male dominated at senior management levels.

The Seven West Media case may be an extreme example, but should not be dismissed, warns Carol Kulik, a research professor in human resource management at the University of South Australia Centre for Workplace Excellence.

"I think what we want to demonstrate with it is that relationships are very unpredictable. The challenge is trying to untangle the personal, romantic, sexual part of it from the business, professional, reporting relationship. The only way those two things are going to work is if you separate them right at the beginning," she says.