A treasure trove of prized momentos from the first moon landing have been found in Neil Armstrong's closet by his wife when she was doing a clearout.

Armstrong, the first man to walk on the moon, died in August 2012 and his wife Carol found the objects from the 1969 lunar expedition languishing at their home in Cincinnati, Ohio.

The objects include a 16mm camera that was mounted on the window of the Eagle lunar module to record the historic landing and Armstrong's "one small step," on a mission that also included Buzz Aldrin.

There was also one of two waist tethers that Armstrong used to support himself during the single rest period on the moon.

The souvenirs, along with other small items, were stashed in a white cloth bag that may have come from a spacecraft. They had been intended to be left behind on the moon but instead appeared to have been intentionally preserved.

"Needless to say, for a curator of a collection of space artifacts, it is hard to imagine anything more exciting," said Allan Needell, of the National Air and Space Museum in Washington.

Armstrong's wife gifted the items to the museum after stumbling upon them.

Soon after Armstrong and Aldrin rejoined Michael Collins in lunar orbit they referenced the items, according to transcripts of voice communications, Needell said on the museum's website.

"You know, that -- that one's just a bunch of trash that we want to take back -- LM parts, odds and ends, and it won't stay closed by itself. We'll have to figure something out for it," Armstrong said to Collins, according to mission transcripts.

The museum noted that no one else had seen the mementos in the 45 years since Armstrong returned from his celebrated mission.

The camera and the tether have been placed on display at the museum.