NSW Opposition Leader Michael Daley is threatening legal action over an article claiming his office phoned a "secret hotline" to transfer a recent speeding fine into his wife's name.

Key points: The story relates to a speeding fine transferred to Mr Daley's wife's name

The story relates to a speeding fine transferred to Mr Daley's wife's name Mr Daley has denied any wrongdoing and said he has referred the matter to police

Mr Daley has denied any wrongdoing and said he has referred the matter to police NSW Police could not yet confirm if a compliant had been lodged

In what the NSW Labor leader claimed was the start of the "dirt files" against him ahead of next month's state election, Mr Daley said he had referred the matter to police and planned to write to the Independent Commission Against Corruption (ICAC) over the "breach of privacy".

The article, published in the Sydney Morning Herald this morning, claimed Mr Daley's staff used what it called a "secret hotline" reserved for MPs to help constituents negotiate fines or issues with Revenue NSW.

The report quoted "records from the hotline" that showed the call was made by Mr Daley's office on August 3, 2017.

The call focused on a car owned by Mr Daley that exceeded the speed limit by up to 10 kilometres per hour driving through Banksmeadow, which sits in his electorate of Maroubra, in May that year.

Mr Daley's office has not denied a staff member called NSW Revenue.

He said the phone line was not a "secret hotline" but a service for MPs to help their constituents.

"Liberal Party dirt units are now trawling through departments' websites," Mr Daley said.

"And now the details of personal citizens — supposedly held under privacy laws — are finding their way into the newspaper."

Mr Daley confirmed his wife Christina was driving his vehicle and the fine arrived in his name.

He said he filled out a statutory declaration that his wife was the driver at the time.

"The fine was reissued in her name," he said.

Michael Daley and wife Christina, who was driving the car at the time, and two children ( ABC News: Philippa McDonald )

"She paid the fine of $114 and got one demerit point.

"I'll be writing to ICAC about the breach of privacy, I'll be referring the matter to the police myself."

NSW Police could not confirm whether a complaint had been lodged.

Premier Gladys Berejiklian said she did not know the "secret hotline" existed, but said Mr Daley had "legitimate questions" to answer.

She said she did not know where the information used in the report came from, but for Mr Daley to raise issues around privacy was like the "pot calling the kettle black".

"I wish I had a dollar for every time the leader stood up with an alleged leaked document from Cabinet," she said.

"But what I think what is of most concern here today, is that the Leader of the Opposition satisfies the public's questions over whether or not he asked his office to do something.

"If he's done nothing wrong, end of story."