A weapon thought to be a submachine gun was found on a slope in Sau Mau Ping yesterday, prompting police to investigate where the gun came from and whether it had been used in any crimes. The rusty weapon was found in what appeared to be a canvass holster, according to police, who believe it may date to the second world war. 'As it is very rusty, we have not established what type of gun is,' said Superintendent Chong Siu-hing, assistant district commander for crime for Sau Mau Ping. He said it was an extendable gun. 'It is about 50cm in length, but the 30cm-long metal handle could be lifted up.' Police said the gun was not loaded and no magazine or ammunition was found. 'It appears to be a submachine gun. We believe it is a genuine firearm, but not workable,' a police investigator said. 'Such weapons are rarely found in Hong Kong. We don't rule out the possibility that it was a military firearm from the second world war.' The weapon will be taken to the Forensic Firearms Examination Bureau at police headquarters in Wan Chai to test whether it is a genuine gun and whether it is still in a working condition. 'If it's found to be genuine, we will investigate the source of the weapon and look into whether it is linked to any crime in Hong Kong,' Chong said. But he said there had been no crimes involving the use of submachine guns recorded in the city in recent years. The gun was found at about 10am when five workers from a company contracted by the Highways Department were cutting grass on a slope off Shun Lee Tsuen Road, opposite Shun Tin Estate. Their supervisor called police. After the discovery, about 40 officers from the police tactical unit conducted a thorough search in the area, but no other firearms or ammunition were discovered. Officers from the Identification Bureau were also called in to take photos and collect evidence such as fingerprints. According to the superintendent, the slope was last weeded about a year ago, but nothing suspicious was found at that time. Chong believes the weapon had been left on the slope for a long time. The slope is located near an abandoned outdoor car park and few people visit the area, police say. Officers from the Sau Mau Ping district crime squad are investigating.