The Singaporean who made the life of American singer Leandra Ramm an ordeal after cyber-stalking her for six years was sentenced to three years jail on Friday.

Colin Mak Yew Loong, 38, had pleaded guilty in court on Dec 4 to sending 31 e-mail messages threatening to kill or harm her.

The prosecution had previously asked for a "global sentence" of between three and four years in jail as Mak had committed a total of 42 offences over a long period of time. But it proceeded on 17 charges, 14 of which were for criminal intimidation.

It all started after he saw the 29-year-old perform on CNN in 2005. They never met, but on one occasion in August 2010, he sent her six threats in one day. The harassment continued until 2011, when the US authorities sought the help of the police here to curb his actions.

Ms Ramm, however, was not the only one. Mak also admitted to harassing and intimidating two other musicians - Hungarian musician Krasznai Tuende Ilona, 30; and Ukrainian Veronika Sakhno, 28; and committing criminal trespass and theft. He had also threatened to kill businesswoman Liew Hwei Ken, 46, in 2010. He claimed she had gone behind his back to engage another person to photograph a model instead of him.

Separately, Mak also trespassed into the pantry of St James Church Kindergarten and stole biscuits in April this year. The next month, he was caught sneaking into a cinema in The Cathay at Handy Road.

For offences that were not related to the criminal intimidation charges, Mak was given a $5,000 fine and one day in jail.