The WA Opposition claims a key Government Minister "systematically misled Parliament" and should resign amid revelations she had long-standing financial links to a stricken renewable energy company.

Key points: Mike Nahan says he believes the Albany wave farm tender process "wasn't proper"

Mike Nahan says he believes the Albany wave farm tender process "wasn't proper" Alannah MacTiernan says she took steps to prevent any conflict of interest

Alannah MacTiernan says she took steps to prevent any conflict of interest Premier Mark McGowan has not confirmed if he knew of her financial links

Documents obtained by the ABC show Regional Development Minister Alannah MacTiernan was paid in cash and shares while working as a business development manager and director for solar microgrid business Energy Made Clean (EMC) in 2011 and 2012, when she was the mayor of the City of Vincent.

EMC went on in 2016 to become a wholly-owned subsidiary of Carnegie Clean Energy, a company awarded a $16 million grant by the McGowan Government, which was overseen by Ms MacTiernan, to create a world-leading wave energy project in Albany.

Carnegie's executive director at the time of that decision was John Davidson, a co-founder of EMC and Ms MacTiernan's former boss.

Ms MacTiernan has previously faced questions in Parliament about her financial interests in EMC, and only confirmed she was given almost 100,000 shares for her work as a director of the company.

Alannah MacTiernan's links to Energy Made Clean were raised in State Parliament. ( ABC News )

The ABC is not suggesting Ms MacTiernan benefited from the Carnegie contract.

Opposition Leader Mike Nahan today called on the Minister to stand down.

"She should resign, she has systematically misled Parliament," he said.

"Before she came into Parliament she prompted a project for a firm she had shares in without a business case.

Timeline: 2011-12: Alannah MacTiernan receives 98,666 shares in EMC Solar as payment for director fees

Alannah MacTiernan receives 98,666 shares in EMC Solar as payment for director fees 2012: EMC Solar renamed EMC Ltd

EMC Solar renamed EMC Ltd 2013: Ms MacTiernan resigns as director after being elected to Federal Parliament, declaring she has EMC Ltd shares

Ms MacTiernan resigns as director after being elected to Federal Parliament, declaring she has EMC Ltd shares 2016: EMC Ltd renamed Clean Energy Investment Holdings

EMC Ltd renamed Clean Energy Investment Holdings 2016: Carnegie buys Energy Made Clean companies; Clean Energy Investment Holdings owns shares in Carnegie Clean Energy

Carnegie buys Energy Made Clean companies; Clean Energy Investment Holdings owns shares in Carnegie Clean Energy 2017: Ms MacTiernan gives Clean Energy Investment Holdings shares to leprosy charity

"She altered the criteria which she personally [set] and gave them funding when they didn't meet the requirement, and then she extended [a deadline] for a period of time, and this firm now is in [administration] and the project is off.

"When the project was first announced, she brought Carnegie to the Labor Party's announcement [which] indicated clearly that they were going to win it."

Shares, cash payments raise questions

Ms MacTiernan has not told Parliament about how much she was paid in cash for her work for EMC, but she confirmed in response to ABC questions it was "less than $30,000", a fact seized upon by Nationals MP Terry Redman.

"From what I've seen in questions she's responded to in Parliament, she has declared she had shares in the company EMC that was later to be a wholly owned subsidiary of Carnegie Clean Energy, but she didn't declare she was paid cash — from what I'm told up to $30,000 — for being within a specific role within the company that was undeclared," he said.

"She was asked about her financial interests and that goes well beyond shares, that goes into cash.

"And she certainly hasn't declared that she took a specific role as a business development manager, so there's a lot of questions to be asked."

Documents obtained by the ABC under freedom of information show the Minister continued to oversee the Albany project after it was won by Carnegie, giving the final tick of approval to its $16 million contract.

MacTiernan 'basically wasted money': Nahan

The Albany Wave Project was axed last month due to Carnegie's financial difficulties, but not before the WA Government made a $2.6 million milestone payment.

Sorry, this video has expired Carnegie's CETO wave energy technology was set to be used for the Albany project

Carnegie, which has received tens of millions of dollars in federal and state government grants over the past decade to develop its wave energy technology, started bleeding cash after it acquired EMC, posting a $64 million loss last year.

Mr Nahan said in his opinion the tender process "wasn't proper from the start", and claimed Ms MacTiernan had gone to "great lengths" to hide details about the contract from Parliament.

"In the end she gave them money when they didn't meet the criteria she personally set for them and lost the state $2.65 million," he said.

"The firm is now in receivership, the project is off and she basically wasted money."

Premier stands by MacTiernan

When questioned whether he knew about Ms MacTiernan's financial ties to EMC, Premier Mark McGowan defended her actions but did not confirm if he was aware of the Minister's history with the company.

Mark McGowan says Ms MacTiernan's links to the company have "all been explained". ( ABC News: Rhiannon Shine )

"Look, I learnt about it, I read your story this morning about it," he said.

"In 2011 she had a role at a company and which wasn't Carnegie. Carnegie purchased that company a few years later.

"The Government then got elected in 2017, entered into a tender process in which Carnegie then won via an independent tender process. I really don't see what the issue is here.

"[Ms MacTiernan] was a private citizen, she was working as a consultant for a company that wasn't even related to Carnegie and she ceased working for it years before Carnegie acquired that company."

Mr McGowan also said Ms MacTiernan gave up her shareholding in EMC two years before it was acquired by Carnegie in 2016.

But a share transfer document shows the 98,666 shares were donated to Leprosy Mission Australia on March 14, 2017, three days before she was sworn in as Minister.

"She gave up her shareholding in a company she had worked for two years before it was acquired by Carnegie, and seven years before we were elected to office and issued a contract to Carnegie," Mr McGowan said.

"At the end of the day, it's all been explained, there's no story here."

Do you know more about this story? Email turner.rebecca@abc.net.au or diss.kathryn@abc.net.au

MacTiernan denies conflict of interest

Ms MacTiernan declined to be interviewed for the story, but at a media conference this morning she rejected the premise that she had any conflict of interest while overseeing the Albany Wave Project tender process.

The failed wave farm project was to be located at Sandpatch near Albany. ( ABC News: Benjamin Gubana )

"I have been very, very public. I have made it clear that between 2011 and 2013 I, for a period, did some work for that company and then remained on as a director for that company," she said,.

"I resigned from that position when I became a candidate for the Federal Election in 2013.

"I had some residual shareholdings and the moment I was invited to be a minister in the McGowan Government, I donated those shares to charity.

"This company at that stage had no involvement with Carnegie, my work was on solar projects and in particular the solar project in Carnarvon which has been successful.

"My only connection with that company after mid-2013 was a residual shareholding of a related company, not actually the main company, and as soon as I became a Minister I donated that to charity so there could be no conflict of interest."