John McCluskey, 45, escaped from an Arizona prison on July 30 with the help of his fiancée, Casslyn Welch, say police. (Mohave County Sheriff's Office)

A law enforcement official says he does not believe two people who robbed a beauty salon in a small Arkansas town are the fugitive Arizona couple.

Benton County Sheriff's Office spokesman Doug Gay said a Gentry, Ark., salon owner who was robbed has said photographs of John McCluskey, 45, and fiancée Casslyn Welch, 44, don't match the two people who were in her shop.

Earlier, the U.S. Marshal's Service said a man and woman matching the description of the fugitive couple held up the beauty salon.

Three days ago, Welch was apparently spotted 2,500 kilometres away at a Montana restaurant on the edge of Glacier National Park, just south of the border with Alberta.

That prompted a major search by U.S. marshals in the northern state and led Interpol to issue an international alert for the couple on Wednesday.

Leads haven't panned out

"We've had multiple, I guess you could call them leads, that we've checked out in the area," Glacier County Undersheriff Jeff Fauque said. "In layman's terms, none of those have panned out," he said.

The Canadian Border Services Agency has put its officers on alert for the pair in case they're thinking of crossing into Canada.

The RCMP in Alberta has also moved a helicopter to Lethbridge to be closer to the U.S. border. But so far, several tips the Mounties have checked out have been dead ends.

The Mounties say there's nothing specific that would lead officers to believe the pair is heading to Canada.

"If I was them and with all of the media coverage saying that they are heading for Canada, I would turn around and head for Florida," said RCMP Sgt. Patrick Webb.

Escaped July 30

McCluskey escaped from an Arizona prison with two other inmates on July 30. His fiancée is believed to have thrown a pair of wire cutters over the prison fence.

The two other escapees were subsequently caught in Wyoming and Colorado.

Forensic evidence has linked the escapees with the murders of a couple in New Mexico. Their bodies were found in the charred wreckage of a camper a week ago.

McCluskey had been serving a 15-year sentence for attempted murder.

With files from The Canadian Press and The Associated Press