He was obsessed with arowanas and went around stealing them from fish tanks and ponds of homeowners. Over two years from September 2010, Ng Thai How, 41, filched 37 arowanas, with a total estimated value of $43,000.

The food stall assistant pleaded guilty to theft in a district court on Friday and was jailed for five months. Court papers state that Ng committed the nine offences with Lim Keng Tat, 40, a cleaning supervisor.

The duo would drive around in the car owned by Lim's father to find homes with arowanas. Ng admitted to returning with Lim late at night on nine occasions to steal the fish from landed properties in Upper Bukit Timah, Serangoon Gardens, Sembawang, Upper Thomson and Telok Kurau.

On one occasion, Tan is said to have driven Ng to a house in Telok Kurau at 2am on March 25 last year. Ng climbed over the perimeter wall of the house and used plastic bags to catch 17 arowanas. He then went over the wall, back to the car to transfer the fish into a styrofoam box filled with water.

By the time they got back to Ng's house in Ang Mo Kio, a fish had died and each man ended up with eight arowanas. The court heard that the estimated value of the 17 fish was $17,000.

In October last year, police arrested the duo separately. Nine fish were recovered from each man. The rest had died. Tan has been charged but not dealt with yet.