New York, New York - A man was being questioned Monday in connection with last week's killing of a top health insurance executive on a New York street, US media reported, as a nationwide hunt for the suspect continued.

The man was quizzed by police in Altoona, Pennsylvania, after being found with a distinctive weapon like that used in the brazen shooting of Brian Thompson, NBC News and others reported, citing sources familiar with the case.

The man was spotted in a McDonald's restaurant in Altoona, a town 300 miles west of New York, by someone who tipped off the authorities, The New York Times reported.

He also had fake IDs similar to those used by the killer ahead of the slaying, the outlet added, reporting that New York detectives were headed to Altoona.

Murder Luigi Mangione's alleged manifesto leaked in full: "These parasites simply had it coming"

Police have been looking into the possibility that the shooter used a long-barrel veterinary gun – normally used to euthanize animals – to commit the murder.

The gunman walked up behind Thompson, a senior figure at UnitedHealthcare – one of the country's largest medical insurers – and shot him dead last Wednesday in front of bystanders, in an attack captured by a surveillance camera and since seen by millions.

Thompson was attending an investor conference in the Midtown business district.

Police have yet to suggest a motive and would not confirm media reports that the words "delay" and "deny" – language often used by insurance companies to reject claims – were written on shell casings found at the scene.

Video footage shows Thompson on the sidewalk outside the New York Hilton Midtown when a man in a hooded top, his lower face covered, approaches from behind, then fires several shots at his 50-year-old victim, who crumples to the ground.

The New York Police Department told AFP that detectives had no update for the media, while the Altoona Police Department did not respond to requests for comment.

Murder UnitedHealthcare killing lays bare US healthcare frustrations

An image released of the smiling suspect was obtained from a youth hostel where the gunman apparently stayed before the hit, with media reporting he had lowered his mask to flirt with a receptionist.

Authorities subsequently located a gray backpack in Central Park thought to belong to the killer containing a jacket and Monopoly money.

During a press conference on Monday afternoon, New York City Mayor Eric Adams confirmed that the police had identified a "strong person of interest" in the case.

Police named the suspect as 26-year-old Luigi Mangione, revealing that officers also found a two-page document detailing frustrations with the health care industry, per the New York Times.

The suspect was found with a gun, silencer, and a fake New ID that matched the one used to check into a hostel in New York.