Australian Taxation Office whistleblower Richard Boyle has broken his silence on the personal toll of speaking up and facing a prison sentence of 161 years if found guilty.

Key points: Former ATO worker Richard Boyle became an internal whistleblower in 2017

Former ATO worker Richard Boyle became an internal whistleblower in 2017 Mr Boyle alleged ATO staff were instructed to use an aggressive debt collection practice on taxpayers without consideration of their circumstances

Mr Boyle alleged ATO staff were instructed to use an aggressive debt collection practice on taxpayers without consideration of their circumstances He has been charged with 66 offences including telephone tapping without consent

Mr Boyle became a whistleblower last year when he exposed abuse of power inside one of the country's most powerful institutions, the ATO, including aggressive debt collection practices.

Speaking exclusively to 7.30, The Age and The Sydney Morning Herald days after his wedding and ahead of a court hearing on Tuesday, he described the past year as hellish.

"I feel like I almost died from the stress. I feel like they almost killed me and were trying to kill me," he said.

Mr Boyle said he lost his job, had a breakdown, suffered chronic insomnia and has had a series of stress-related heart issues.

Louise Beaston and Richard Boyle on their wedding day. ( Supplied: Richard Boyle )

"I've had some dark moments," he said. "It's taken a huge toll on my mental health. I couldn't work. I couldn't sleep and my health spiralled into what I describe as a devastating situation."

In January he was charged with 66 offences, including telephone tapping without the consent of all parties and making a record of protected information.

"It sent me into a tailspin," he said. "It was devastating."

After receiving the charges, he and his fiancee Louise Beaston decided they could not hold off their marriage plans.

"We decided we couldn't wait any longer," he said. "We decided we needed to celebrate the little things in life and continue on together."

Ms Beaston said planning the wedding, which was held in the State Library of South Australia in Adelaide last weekend, proved a great distraction.

"It was a total leap of faith to go ahead and make this day happen this year, and our friends and family couldn't be happier for us," she said.

"It was just nice to have a day where you didn't have to think about things."

'From the raid I have been in a state of anxiety'

Richard Boyle outside his Adelaide home after it was raided by the AFP on April 4, 2018. ( ABC News: Simon Goodes )

Mr Boyle became an internal whistleblower in 2017 when he made a disclosure under the provisions of the Public Interest Disclosure (PID) Act 2013 to the ATO. His allegations were investigated by a senior ATO investigator and dismissed.

He alleged that some ATO staff were instructed to use an aggressive debt collection practice known as garnishee notices, which allows the ATO to seize funds from the bank accounts of Australian taxpayers without notice or consideration of their circumstances.

The ATO offered him a settlement over an alleged breach of the Public Service Code of Conduct, offering him a payout and a statement of service, with no admission of liability, on the proviso he signed a gag order. He declined and went public in a joint media investigation with the ABC.

His home in Edwardstown, south-west of Adelaide, was raided and his laptop and phone seized. At the time, the ATO said protecting taxpayer confidentiality was critical for the integrity of Australia's tax and super systems.

"From the raid, I have been in a state of anxiety wondering what was going to come next," he said.

But he said if people did not speak up, "how are we going to change things?"

Senator says charges should be withdrawn

Senator Rex Patrick is calling for the Government to drop the charges against Mr Boyle. ( ABC News: Gary-Jon Lysaght )

Senator Rex Patrick, whose Centre Alliance party holds a crucial two seats in the Senate, has become a powerful ally. He is calling on the Government to intervene and drop the charges.

He said Attorney-General Christian Porter had the power to overturn the charges if it was in the public interest. He said there have been two inquiries that had vindicated Mr Boyle's allegations.

"They have shown that there was improper conduct taking place inside the Adelaide ATO office, and the ATO now concedes that they have fixed that problem, and yet he finds himself facing a jail term," Senator Patrick said.

"The Attorney-General needs to withdraw these charges on the basis it's not in the public interest … he has the power, he acknowledges that, but he simply thinks it's too an unusual a power to use."

He said the treatment of Mr Boyle had created a chilling situation for whistleblowers in Australia.

"There's a very strong message that's being sent to people inside the ATO — if you blow the whistle, you're history," Senator Patrick said.

In a statement, Mr Porter defended his decision, saying the power of the Attorney-General to reverse an independent decision of the Commonwealth Department of Public Prosecutions should only be used in the most extraordinary and exceptional circumstances.

"This narrow power has in fact never been used since it was established 36 years ago," he said.

Mr Boyle said he hoped something would change.

"It's taken a terrible toll. It's relentless," he said.

"It doesn't seem like it'll stop any time soon."

In a statement, an ATO spokesperson said: "The ATO cannot comment on prosecution decisions, which are made by the CDPP, however, we note that the charges relating to Mr Boyle concern the alleged disclosure of confidential taxpayer information, recording and disclosing tax file numbers, and the use of listening devices."

Adele Ferguson is an investigative journalist and columnist with The Sydney Morning Herald and The Age. Read more by Adele here.