The woman who filed a sexual harassment complaint against outgoing Deputy Prime Minister Barnaby Joyce says she did it to speak up against inappropriate behaviour.

Key points: Former WA Rural Woman of the Year Catherine Marriott said she never intended for the issue to become public

Former WA Rural Woman of the Year Catherine Marriott said she never intended for the issue to become public Ms Marriott said she asked National Party to undertake a "formal and confidential" investigation

Ms Marriott said she asked National Party to undertake a "formal and confidential" investigation Barnaby Joyce previously called her allegation "spurious and defamatory"

Catherine Marriott said she made the complaint because she wanted Mr Joyce to be accountable.

In a statement, Ms Marriott said she never intended for the issue to become public and had asked for the National Party to undertake a "formal and confidential" investigation into the incident.

"I requested that … to ensure there is accountability in relation to the incident I raise, and to prevent this type of inappropriate behaviour towards women in the future," Ms Marriott said.

"This complaint was not made solely to address the incident against me — it is about speaking up against inappropriate behaviour by people in powerful positions.

"I will await the outcome of this investigation before determining any future action or commenting further."

Ms Marriott is a former West Australian Rural Woman of the Year.

Mr Joyce has previously called her allegation "spurious and defamatory" — and has called for the matter to be referred to the police.'

Catherine Marriott says she wanted to hold Barnaby Joyce accountable. ( ABC Rural: Vicky Biorac )

"I have asked for the right of that person who's made the allegation and I've asked for my right to defence that that be referred to police," Mr Joyce said yesterday.

Mr Joyce declined to discuss the allegation further.

The complaint became public this week, before Mr Joyce confirmed he would be resigning as Nationals leader.

He was already under pressure to resign, following the publication of a story confirming he had an affair with a member of his staff, Vikki Campion, and they are now expecting a baby boy.