The suicide of a Victorian policewoman has highlighted the heavy toll emergency services work takes on officers and prompted calls for better suicide prevention measures.

The senior constable took her own life while on duty at a centre which helps victims of sexual assault in Melbourne's south-east, on Monday.

She was a mother in her mid-30s and had been a policewoman for more than 12 years.

Her colleagues have been offered counselling, Police Association secretary Ron Iddles said.

"I think it's always sad when we actually lose a member, but when a member takes their own life I think it's far, far more tragic," he said.

Mr Iddles said 220 police officers had taken sick leave for psychological problems like depression, anxiety and post-traumatic stress in the last year.

A Police Association survey of 3,500 members found 77 per cent had trouble sleeping because of their work, and 8 per cent had been diagnosed with post-traumatic stress disorder over the past three years.

Mr Iddles said the policewoman's death demonstrated the importance of cultural change, so people could seek help without fearing the consequences.

"I think in the past there has been a stigma in relation to putting your hand up and saying, 'I'm not coping', for fear that you might lose your job," he said.

Four police suicides in recent years prompted Victoria Police to launched a nationwide review.

It is also working on a smartphone app to help officers suffering from mental illness.

Police suicide 'relatively rare end point'

An investigation will look at the circumstances surrounding the death of the leading senior constable.

Professor Sam Harvey from the Black Dog Institute said the death was a reminder of the mental health consequences of emergency service work.

"With the police I guess there's a particular problem, while a lot of them are having mental health problems, they're also carrying a weapon around," he told 774 ABC Melbourne.

"This is thankfully still a relatively rare end point."

About one in 10 emergency services workers show symptoms of post-traumatic stress disorder (PTSD), Professor Harvey said.

He said that meant there were lessons to be learnt from the 90 per cent of workers in the field who are more resilient to mental health issues.

"So we're trying to learn from that and trying to test whether we can train all new emergency workers to learn new resilience techniques," Professor Harvey said.

Victoria's Mental Health Minister Martin Foley said the State Government would work closely with police to examine how the mental health of officers could be improved.

"We look forward to working with police command about understanding what it is that drives our frontline emergency services workers to take such a sad step," he said.