SINGAPORE - When officers from the Central Narcotics Bureau (CNB) visited a drug offender's Yishun flat, he told them he had nothing to surrender.

But when they carried out a search, they found an airsoft pistol, seven ammunition cartridges, a packet of cannabis and an explosive known as R-Candy.

Odd-job worker Kang Chun How, 23, was sentenced to 11 months' jail and a fine of $9,000 on Thursday (Sept 20) after pleading guilty to being in possession of the illegal items as well as one count of consuming cannabis.

Deputy Public Prosecutor Kumaresan Gohulabalan said the officers took Kang to a CNB office at Jurong Police Divisional headquarters after searching his flat on Sept 16, 2015.

Kang had claimed that he obtained four of the cartridges from his seniors when he was a secondary school student in 2010. He also claimed that he received the other three from a friend known only as Ian.

However, he was unable to provide their contact details to the police.

Investigations revealed that he had been in possession of the airsoft pistol since 2012.

His lawyer, Mr Lee Wei Liang, told District Judge Sandra Looi that his client had bought it from a website out of curiosity.

The lawyer added: "The parcel cleared customs and was delivered to the accused at his home. After receiving the replica, the accused dismantled it to find out more about its internal mechanisms and the way it worked. After fiddling with the replica for several months, the accused put it away."

DPP Kumaresan said a bottle marked R-Candy was also uncovered in Kang's home.

It contained about 55g of white substances which were found to include potassium nitrate and sucrose. Kang had learnt how to make R-Candy or "rocket candy" from the Internet, the court heard.

Mr Lee said that his client had developed an interest in "kitchen chemistry" due to his "curious nature".

The lawyer added: "The accused had no use for the R-Candy and kept it in a container, intending to dispose of it. However, he was unable to find time to do so.

"When the authorities seized the R-Candy, a considerable amount of time had elapsed and the moisture in the air would have rendered the R-Candy impotent and incapable of ignition."

Kang is now out on bail of $30,000 as he had to settle some personal affairs. He was ordered to surrender himself at the State Courts on Oct 4 to begin serving his sentence.