An inert rocket of the type used to carry a nuclear warhead has been found in the garage of a home of a deceased resident in Washington state, police said.

Bellevue police responded on Thursday to a report of a military-grade rocket in the garage of a home in the city across Lake Washington from Seattle.

Police said an Air Force museum in Dayton, Ohio, had called on Wednesday evening to report an offer to donate the item, which a neighbour said had been purchased at an estate sale.

Bomb squad members inspected the rusting object and found it was a Douglas AIR-2 Genie (previous designation MB-1), an unguided air-to-air rocket that is designed to carry a 1.5 kt W25 nuclear warhead.

There was no warhead attached and there was no rocket fuel – “essentially meaning that the item was an artefact with no explosive hazard”.

“Because the item was inert and the military did not request it back, police left the item with the neighbour to be restored for display in a museum,” police said.

According to the Air Force Armament Museum Foundation, the unguided air-to-air rocket was used by the US and Canada during a period of the Cold War when interception of Soviet strategic bombers was a major military concern.

In July 1957, a Genie was launched at 18,000ft (about 5,500 metres) from an F89J interceptor and detonated over Yucca Flats, Nevada, the first and only test detonation of a US nuclear-tipped air-to-air rocket.

“And we think it’s gonna be a long, long time before we get another call like this again,” police said on Twitter, adding a rocket emoji.