Robert Lafreniere said his office has received "no official confirmation" from Panamanian authorities about reports the well-known doctor died of cancer this week.
"It seems to us essential and a priority to rapidly obtain proof so we can take the appropriate steps regarding the charges of fraud, conspiracy and money laundering (Porter) is facing," Lafreniere said in a statement.
The Crown alleges Porter received part of a $22.5-million payment from Montreal-based engineering giant SNC-Lavalin in order to fix the call for tenders to ensure the firm received the lucrative $1.3-billion contract to build a megahospital in Montreal.
News of the investigators travelling to Panama came the same day as Crown officials in Quebec said they also are seeking official documents and corroborative evidence of Porter's death.
Without such evidence, the fraud charges against Porter will stand, Crown prosecutor Marie-Helene Giroux said in an interview.
"I am waiting for official confirmation," she told The Canadian Press. "Until then, for me, the file is not closed."
Porter's biographer, Jeff Todd, published a statement Wednesday to say Porter's doctor confirmed his patient had succumbed to cancer in Panama, where he had been detained since May 2013 as he fought extradition to Canada.
On Thursday, Todd published a second statement, reportedly from Porter's family, confirming the death.
"We remember a man of incomparable intellect, wit, charm and integrity whose focus was always on providing the best care he could for his patients," it said. "He achieved more in his 59 years than most even dream to accomplish in a lifetime."
Giroux said a post on a website is "really not enough."
She added her office has started preparing an official request to receive proof of Porter's passing, such as a death certificate signed by a doctor.
Porter was once one of the most highly respected doctors in the country. He published hundreds of research articles in medical journals and pioneered concepts in radiation therapy.
In 2004 he was appointed director general of the McGill University Health Care Centre in Montreal and led the project to build the so-called superhospital near the city's downtown core.
Porter's wife, Pamela Porter, was sentenced in December to 33 months in prison after she pleaded guilty to two counts of money laundering in connection with her husband's case.
She was given a conditional release from prison on June 10.
The other people accused in the bribery and fraud case are awaiting trial.
Quebec Premier Philippe Couillard, who founded a medical-related company with Porter in 2010 before his return to politics, was asked Thursday about the reports of the death.
"My only comment...is this is a sad ending for a very sad story," he told a news conference in Roberval, Que.
Couillard has said the company conducted no business and that there were no financial statements before it dissolved in 2012.
Opposition Leader Pierre Karl Peladeau took to Facebook on Thursday to highlight the ties between the two men.
The Parti Quebecois leader posted an old and widely circulated photo of Couillard and Porter together, with the caption: "Mr. Premier, like many other citizens, I offer you my sympathies regarding the news of the death of your friend and former associate, Dr. Arthur Porter."
The Facebook mocking comes amid a public spat between Peladeau and the Couillard government over changes to tax credits for TV production companies. The modifications mean that a firm owned by Peladeau's fiancee, Julie Snyder, is no longer eligible for the credits.