A Republican donor and operative from Chicago's North Shore who said he had tried to obtain Hillary Clinton's missing emails from Russian hackers killed himself in a Minnesota hotel room days after talking to The Wall Street Journal about his efforts, public records show.

In mid-May, in a room at a Rochester hotel used almost exclusively by Mayo Clinic patients and relatives, Peter W. Smith, 81, left a carefully prepared file of documents, including a statement police called a suicide note in which he said he was in ill health and a life insurance policy was expiring.

Days earlier, the financier from suburban Lake Forest gave an interview to the Journal about his quest, and it began publishing stories about his efforts in late June. The Journal also reported it had seen emails written by Smith showing his team considered retired Lt. Gen. Michael Flynn, then a top adviser to Republican Donald Trump's campaign, an ally. Flynn briefly was President Trump's national security adviser and resigned after it was determined he had failed to disclose contacts with Russia.

At the time, the newspaper reported Smith's May 14 death came about 10 days after he granted the interview. Mystery shrouded how and where he had died, but the lead reporter on the stories said on a podcast he had no reason to believe the death was the result of foul play and that Smith likely had died of natural causes.

However, the Chicago Tribune obtained a Minnesota state death record filed in Olmsted County saying Smith committed suicide in a hotel near the Mayo Clinic at 1:17 p.m. on Sunday, May 14. He was found with a bag over his head with a source of helium attached. A medical examiner's report gives the same account, without specifying the time, and a report from Rochester police further details his suicide.

In the note recovered by police, Smith apologized to authorities and said that "NO FOUL PLAY WHATSOEVER" was involved in his death. He wrote that he was taking his own life because of a "RECENT BAD TURN IN HEALTH SINCE JANUARY, 2017" and timing related "TO LIFE INSURANCE OF $5 MILLION EXPIRING."

Family photo Peter W. Smith Peter W. Smith (Family photo) (Family photo)

He had been staying at the hotel for several days and had extended his stay at least once but was expected to check out on the day his body was found. "Tomorrow is my last day," Smith told a hotel worker on May 13 while he worked on a computer in the business center, printing documents, according to the police reports.

One of Smith's former employees told the Tribune he thought the elderly man had gone to the famed clinic to be treated for a heart condition. Mayo spokeswoman Ginger Plumbo said Thursday she could not confirm Smith had been a patient, citing medical privacy laws.

The Journal stories said that on Labor Day weekend last year Smith assembled a team to acquire emails the team theorized might have been stolen from the private server Clinton had used while secretary of state. Smith's focus was the more than 30,000 emails Clinton said she deleted because they related to personal matters. A huge cache of other Clinton emails were made public.

Smith told the Journal he believed the missing emails might have been obtained by Russian hackers. He also said he thought the correspondence related to Clinton's official duties. He told the Journal he worked independently and was not part of the Trump campaign. He also told the Journal he and his team found five groups of hackers — two of them Russian groups — that claimed to have Clinton's missing emails.

Smith had a history of doing opposition research, the formal term for unflattering information that political operatives dig up about rival candidates.

For years, former Democratic President Bill Clinton was Smith's target. The wealthy businessman had a hand in exposing the "Troopergate" allegations about Bill Clinton's sex life. And he discussed financing a probe of a 1969 trip Bill Clinton took while in college to the Soviet Union, according to Salon magazine.

Investigations into possible links between the Russian government and people associated with Trump's presidential campaign are underway in Congress and by former FBI chief Robert Mueller. He is acting as a special counsel for the Department of Justice. Mueller spokesman Peter Carr declined to comment on the Journal's stories on Smith or his death. Washington attorney Robert Kelner, who represents Flynn, had no comment Thursday.

Smith's death occurred at the Aspen Suites in Rochester, records show. They list the cause of death as "asphyxiation due to displacement of oxygen in confined space with helium."

Rochester police Chief Roger Peterson on Wednesday called Smith's manner of death "unusual," but a funeral home worker said he'd seen it before.

An employee with Rochester Cremation Services, the funeral home that responded to the hotel, said he helped remove Smith's body from his room and recalled seeing a tank.

The employee, who spoke on condition he not be identified because of the sensitive nature of Smith's death, described the tank as being similar in size to a propane tank on a gas grill. He did not recall seeing a bag that Smith would have placed over his head. He said the coroner and police were there and that he "didn't do a lot of looking around."

"When I got there and saw the tank, I thought, 'I've seen this before,' and was able to put two and two together," the employee said.

An autopsy was conducted, according to the death record. The Southern Minnesota Regional Medical Examiner's Office declined a Tribune request for the autopsy report and released limited information about Smith's death. A spokeswoman for AXA Equitable Life Insurance Co., listed in documents recovered by police as Smith's insurance carrier, had no immediate comment.

The Final Exit Network, a Florida-based nonprofit, provides information and support to people who suffer from a terminal illness and want to kill themselves. Fran Schindler, a volunteer with the group, noted that the best-selling book "Final Exit," written by Derek Humphry in 1991 and revised several times since, explains in detail the helium gas method.