At least six West Australian Liberal MPs including Peter Katsambanis have been sent death threats ahead of Saturday's state election.

The ABC understands letters were sent to the home addresses of at least six Liberal candidates, including a former minister.

The author accuses the recipients of "stuffing up their life and business" and directly threatens "women and children".

One of the recipients is Upper House MP and candidate for the seat of Hillarys Peter Katsambanis.

"It's disconcerting for me, it's disconcerting for my family," Mr Katsambanis said.

"When people make direct threats to people's homes about their family, this is no longer fair game in politics.

"This is despicable behaviour."

Mr Katsambanis reported the matter to police and provided them with the letter.

He said the election campaign had been particularly nasty.

"This campaign has been littered with threats and attacks on myself, on my wife, on campaign workers and volunteers," he said.

"This is just one more.

"It's clearly designed to take my attention away in the last few days of the campaign, but it's not going to work."

Concern about address publication

It is understood the police dignitary protection unit has been notified.

WA Police confirmed they were investigating the letters.

Mr Katsambanis describes the threats as "despicable". ( ABC News: Andrew O'Connor )

"At this time I can't provide details of what was written in the letters and the investigation is ongoing," a spokesman said.

Some MPs involved have raised concerns their home addresses were accessed after being published in The West Australian newspaper as part of an election notice by the WA Electoral Commission.

Mr Katsambanis said publishing home addresses was not appropriate.

"Given the unstable global environment we live in, the act needs to be changed as soon as possible after the election," he said.

"Suburb details should be enough in this day and age."

The commission said it was required by law.

"Under the Electoral Act the Commission is required to publish candidate nomination details, which include the address that each candidate provides on their nomination form," a spokesperson said.

"However, there is provision for anyone to enrol as silent elector.

"In such cases a candidate's address details would not be published."