Image copyright Allen Henson Image caption Model Shelby Carter, said to be a friend of photographer Allen Henson, was filmed while topless on 9 August 2013

The owners of New York's Empire State Building have sued a photographer who shot images of a topless woman on the skyscraper's observation deck.

They say Allen Henson's actions in August were "inappropriate" at a family tourist attraction and that he lacked permission to hold a photoshoot there.

The owners seek $1.1m (£670,000) in damages.

Henson says the photos were taken of a friend on his personal cellphone and have "zero commercial value".

The New York-based photographer and Iraq war veteran told the BBC he first learned of the lawsuit through the news media on Monday and had not yet retained a lawyer.

'A great view'

Image copyright Allen Henson Image caption Allen Henson, an Iraq war veteran, says tourists were taking photos without permission, too

"It wasn't a photoshoot," he said, adding the images were taken of a good friend, Texas-based model Shelby Carter, on the 86th storey observation deck.

"We thought it would just be wonderful, a great view… no harm no foul," he added. "Nobody was injured, no children were around."

In a lawsuit filed in New York State Supreme Court, the companies that own the building and operate the observation deck argue the incident threatened their ability to ensure a "safe, secure and appropriate place for families and tourists".

ESRT Observatory and ESRT Empire State Building also claim Henson lacked the required permission to use the trademarked image of the popular tourist spot, which attracts four million visitors annually.

The photographer told the BBC the photos were not intended for commercial distribution and he had not made any money from them since they were taken.

He also added that many of the tourists around him on 9 August were also taking photos and video on their personal mobile phones without prior permission.

"It's not logical," he said of the lawsuit. "They've made a mistake here."