In one of her final moves as Canada's ethics and conflict of interest commissioner, Mary Dawson found that Bill Morneau and a family member didn't benefit from insider information when they sold shares in his family's pension company, Morneau Shepell, in the fall of 2015.

In a letter dated Jan. 5 and addressed to Morneau, Dawson said the income tax increase for Canadians earning more than $200,000 was publicly announced on Nov. 4 and Morneau sold his shares on Nov. 30. The legislation was tabled on Dec. 7.

"The act prohibits the use of insider information obtained in his or her position by a public office holder and that is not available to the public, which, in light of the above [reasons] was not the case in this instance," she said.

Dawson investigated the sale at NDP MP Nathan Cullen's request. Conservative finance critic Pierre Poilievre also wrote to her office. Poilievre had argued the timing of the share sale was no coincidence as the share price later took a dip, and he has sought to tie the depreciation to the tax hike.

The finance minister had also come under fire after news reports revealed the Bank of Canada had an $8 million contract with Morneau Shepell to manage pensions and benefits.

But Dawson also dismissed any notion that Morneau, who is the minister responsible for the Bank of Canada, influenced the bank's decision to renew the contract.

"I am satisfied that, as minister of finance, you had no involvement in the Bank of Canada's decision of the renewal of the Morneau Shepell Inc. contract," Dawson said in the letter.

'Terrible judgement'

"We have received the letter from the Ethics Commissioner and we are pleased with the outcome," said a spokesperson for Morneau.

"The minister has gone above and beyond the initial recommendations from the ethics commissioner by divesting all his family's holdings in his former company, donating upwards of $10 million to charity and setting up a blind trust."

Poilievre responded to the decision Monday saying, regardless of Dawson's decision, ministers shouldn't sell shares the way Morneau did.

"Conservatives believe it is unwise for ministers to buy or sell shares in the weeks immediately before the introduction of tax measures. Finance Ministers should lead by example. It is not good enough for ministers to boast that their actions are not illegal," he said in an email to CBC News.

Poilievre also noted that Morneau "remains under investigation for introducing a pension bill that could have impacted his pension company."

Pension bill investigation still pending

Dawson's office hasn't released the results of that investigation — regarding Morneau's role in introducing Bill C-27 while he still owned shares in his family's company.

Cullen and Poilievre also both wrote to Dawson asking her to look into whether Morneau benefited financially when Bill C-27 was introduced.

Monday Dawson told CBC News that the examination into that issue "remains active."

Cullen has argued that, because Morneau held about one million shares at the time, he could make millions if the bill passed.

Kelly Cryderman, Susan Smith, Robin MacLachlan and Rachel Curran discuss Mary Dawson finding that Bill Morneau and a family member didn’t benefit from insider information when they sold shares in his family's pension company, Morneau Shepell, in the fall of 2015. 9:02

Dawson's latest ruling comes after months of controversy for Morneau over his ownership of the company's shares and his use of private corporations to hold his assets — including one he failed to declare until September, which holds a villa in France.

Morneau paid a $200 fine for failing to declare that company when he was elected.

Dawson's last day as ethics commissioner is Monday. Mario Dion has been tapped to replace her.