Former Liberal MP Raj Grewal, who temporarily stepped away from federal politics last year to deal with a compulsive gambling problem, will not run in the upcoming federal election, CBC News has learned.

The Brampton East MP left the Liberal caucus last December, weeks after the Prime Minister's Office said he was receiving treatment from a health professional "related to a gambling problem that led him to incur significant personal debts." He sat as an Independent before Parliament was dissolved for the election.

The Globe and Mail reported at the time that Grewal had accumulated debt amounting to more than $1 million.

Grewal's debts and position as an MP — one who sat on the finance committee — prompted opposition politicians to question the government in the House of Commons about what it knew of Grewal's troubles and when.

"We've learned that the gambling debts of the Liberal MP for Brampton East came to light as the result of a police wiretap," Conservative MP Mark Strahl said in November 2018, citing media reports.

"The wiretaps were part of an OPP investigation into, quote, 'particularly shady guys' suspected of money laundering and terrorist financing. When did the Prime Minister's Office first learn about this serious investigation involving a sitting Liberal member of Parliament?"

NDP MP Nathan Cullen also grilled the government in the Commons, demanding answers about Grewal's time on the finance committee — especially the questions he asked senior RCMP witnesses about how they investigate money laundering.

"The Liberal MP from Brampton East was appointed to the finance committee by the prime minister, where he asked troubling questions of senior law enforcement officials about how to avoid detection. This raised red flags with the RCMP," Cullen said.

Personal debts

CBC News reported that Grewal's most recent filing with the ethics commissioner's office at the time showed he had been carrying lines of credit with three separate banks: RBC, TD Bank and Scotiabank. He and another individual also held an HSBC mortgage.

His assets listed in the ethics filing included joint ownership of a residential investment property in Toronto.

That filing also showed Grewal had earned employment income from ZGemi Inc., a general contractor located in Brampton, and from the law firm Gahir & Associates, on top of his MP's salary.

The ethics filing did not reveal the amounts owed on the lines of credit or the mortgage.

Grewal returning to legal practice

In early December, Grewal posted an 11-minute video to his Facebook page in which he addressed the allegations against him in the House of Commons and in a series of media reports.

The MP said he got into the habit of frequenting the Hilton hotel in Gatineau, Que., which houses the Lac-Leamy Casino.

What started as recreational blackjack spiraled into a "significant problem," he said, as he accumulated gambling debts in high-stakes games over three years — debts he hid from his friends and family.

Grewal said he routinely borrowed from his loved ones to continue the pattern and no money was obtained illegally.

"I want to make it clear, that every single personal loan made to me was by cheque. Everybody has been paid back, and every loan and repayment is transparent and traceable," he said in the video.

He said his problem gambling was hidden until early November, when he revealed his addiction to his family. Shortly after that, on Nov. 19, Grewal said he notified Trudeau's office about his mental-health issues.

Planned to resign and changed his mind

The PMO and Grewal initially said he would resign his seat.

"Based on these circumstances, we agreed that his decision to resign as member of Parliament for Brampton East was the right one," the PMO statement said at the time. "We hope he receives the support he needs."

However, by the end of January this year he changed his mind and announced he would stay on as an Independent MP.

Grewal told CBC News Wednesday that he decided to serve out his term because that's what he promised his constituents. He said he is grateful for the support voters have shown him and will return to his private legal practice in Brampton after the election.