SINGAPORE - A sales manager and his friend who met for breakfast came up with more ideas than just what to eat.

They decided to spy on unsuspecting women and take videos of them changing their clothes.

While father-of-three Lo Ji Sum would record the videos, shipping executive Khoo Fook Mun would act as a lookout.

On Tuesday (July 31), Lo, 44, was sentenced to 12 weeks' jail and fined $20,000 after pleading guilty to two counts each of insulting a woman's modesty and transmitting obscene materials. He also admitted to being in possession of obscene and uncertified films.

Deputy Public Prosecutor Gail Wong told the court that Lo and Khoo, also 44, were members of the Sammyboy Forum, which she called "a predominantly sex-themed online website containing hundreds of threads sharing obscene materials".

She said the duo used the site and other similar platforms to watch videos of women in various states of undress. The court heard that the two men have known each other for more than 20 years after meeting through the forum.

Their plan was hatched over breakfast at a coffee shop in July 2016, DPP Wong said.

"They decided to do this at around 8am as they opined that women would be getting ready for work at that time. Though they did not carry out the plan that day, they subsequently exercised it on multiple occasions," she added.

They targeted blocks in Mei Ling Street and Stirling Road near Commonwealth Avenue and looked out for units that had the lights on. They would then go up to the flats to see if there were any women inside.

On their modus operandi, DPP Wong said: "They would pick units with silver grilles and windows so that the accused's phone, which was silver, would be less visible."

In all, they took videos about 15 times in July 2016, she added.

On July 25, a pair of sisters were getting ready for work when Lo started recording them by sliding his mobile phone through the window louvres of their bedroom, which faces the common corridor.

One sister spotted the device when she turned round and started shouting. The two men fled the scene. The police were notified and officers later managed to establish the two men's identities.

Lo and Khoo arranged to return to the same neighbourhood a week later to commit similar offences. Khoo was waiting for Lo at a lift lobby when officers arrested him and then Lo.

Items seized from Lo included thumb drives and a MacBook Air laptop computer. The devices were later found to contain 1,424 uncertified films and 413 obscene ones, DPP Wong said.

The case against Khoo is pending.