It is unclear if he remains under investigation, or why he was considered a person of interest.
An FBI spokeswoman said she could not immediately comment Tuesday. He says Paddock told him he was going to put on a "light show" with the tracer ammunition he purchased.
While Danley and Haig were named by law enforcement as persons of interest in search warrant affidavits, neither have been charged with a crime.
Records showed Haig owns Specialized Military Ammunition LLC.
Lombardo said January 20 that the FBI had an open investigation into an unnamed person of interest, although it's not clear whether that was Haig, and the sheriff said repeatedly that Paddock was the only shooter. Haig told Newsweek that he had been interviewed by agents with the Bureau of Alcohol, Tobacco, Firearms and Explosives.
"I have to think that if it was really, really serious or there was something that they thought I did that was wrong, [the agents] would have been kicking my door down", Haig said.
Neither the police, the Federal Bureau of Investigation nor the USA attorney's office have commented on whether Haig is still considered a person of interest in the investigation, however Las Vegas sheriff Joe Lombardo said earlier this month that investigators believed Paddock had acted alone.
The Arizona ammunition maker embroiled in the Las Vegas massacre claims he sold the gunman hundreds of bullets without a clue he planned to fire into a crowd, killing 58 people.
Clark County District Court Judge Elissa Cadish ordered the documents released after CNN and other media outlets sued to obtain the Las Vegas Metropolitan Police Department search warrants related to the October 1 shooting.
The company's webpage says the business is closed indefinitely.
The Las Vegas Review-Journal identified the person of interest as Douglas Haig.
Haig told Newsweek he hadn't sold ammunition reloading components "for a long time" and said he had asked the company hosting the Specialized Military Ammunition website to take it down.
The newspaper published the name online. She is not likely to face any charges, according to authorities involved with the investigation.
Authorities say she's not likely to face criminal charges.
United States investigators had maintained he had acted alone.
Redacted autopsy reports of the 58 victims slain in the October 1 mass shooting will be released "as soon as possible" following a Tuesday court order, according to the Clark County coroner's office.
The coroner has the option of appealing the autopsies ruling to the Nevada Supreme Court.
On Jan. 20, Lombardo told reporters that the "FBI has an ongoing case against an individual of federal interest", but declined to identify the person or say what their suspected connection was to the shooting. The Las Vegas Review-Journal used an unredacted copy and identified Mr. Haig.