Chinese authorities have dismissed reports that a suspected China-made artillery shell was found in a commercial shipping container in Papua New Guinea, saying it is a “shell-shaped wine bottle”.

“It poses no danger at all,” the Chinese embassy wrote in a Facebook post on Tuesday, drawing sceptical comments.

Police in Port Moresby arrested four Chinese nationals last Friday after the 32kg object was found at a construction site in the capital city.

Authorities were looking into whether it was a live device, local reports said then, with police commissioner David Manning describing it as “a very concerning discovery”.

In a report on Wednesday, the Australia Broadcasting Corporation cited unnamed sources identifying the object as an undetonated 130mm Chinese Type 59 Artillery Projectile that contains chemical explosives and a fuse. The BBC has not independently verified this.

Papua New Guinea police had earlier dismissed speculation that the object was “merely a dummy”, local newspaper Post Courier said.

However, the Chinese embassy said in its statement that it is “virtually impossible” for an illegal military-grade artillery shell to be smuggled out of China to Papua New Guinea.

“China enforces some of the world’s strictest firearm control laws and regulations,” it wrote, adding that China is “widely recognised as one of the safest countries globally”.

Some Facebook users appear unconvinced.

“What sort of wine bottle weighs 32 kilograms?” wrote one of them.

Another wrote that the object bore no labels indicating that it’s a wine bottle.