SINGAPORE - A former investigation officer who repeatedly forged work documents to avoid having to perform his duties was jailed for 15 months on Thursday, in a unique case.

Then a sergeant attached to the Bedok police division's investigation branch, Norazly Joihani, 33, committed 60 offences in all between January 2009 and November 2010. These comprised mainly forgery.

He tampered with daily monitoring returns lists, which show police reports and the corresponding assignments and as a result did not need to start investigations into the matters as directed by his superior. Follow-up action into the 32 cases involved, including six unnatural deaths that required coroner's inquiries and 18 active matters, was not carried out until his actions came to light.

Norazly, whose services were terminated in March last year, also forged the acknowledgement forms for the return of case exhibits that had been seized during investigation. He returned the acknowledgment forms to the division store and the rightful owners never got their property returned to them. He kept the items instead.

Passing sentence, District Judge Toh Yung Cheong said Norazly's actions had diminished public trust and confidence in the efficiency of the police force here, and had undermined the integrity of Singapore's criminal justice system as a whole.

The maximum penalty for forgery is a jail term of four years and a fine. Forgery for the purpose of cheating carries up to 10 years in jail and a fine.