SINGAPORE - A former senior bank officer was jailed for 12 weeks on Friday (Jan 8) for taking upskirt videos of 21 women in one day using a pinhole camera attached to the tip of an umbrella.

Ng Yap Tiong, 44, was working in Westpac Banking Corp when he committed the 21 offences at Far East Square, Pekin Street, and Wisma Atria shopping centre in Orchard Road on May 27, 2014.

He pleaded guilty to seven charges a year ago. A hearing in which experts from both the defence and prosecution gave evidence was held last December.

Deputy Public Prosecutor Chee Min Ping had told the court that Ng drove to Takashimaya Shopping Centre in Orchard Road that evening to take upskirt videos of females.

He attached a pinhole video camera to the tip of his umbrella and took it with him to Wisma Atria, where he started walking around scouting for victims.

He entered Charles and Keith store and walked close to a 28-year-old woman, slanting his improvised video-recording device towards her and started to record an upskirt video.

The woman's boyfriend called the police ,who came and arrested Ng.

Further investigation showed that Ng had on various occasions taken upskirt videos of unknown women.

He had taken two more women's upskirt videos at the same shoe store and four at Watson's at Basement 1 of the shopping mall.

During December's hearing, an Institute of Mental Health psychiatrist had testified that Ng was suffering from mild depression; but Ng's psychiatrist Tommy Tan said Ng's mental disorder was the main contributing factor to his offending behaviour.

District Judge Hamidah Ibrahim sentenced him to four weeks' jail on each charge and ordered three to run consecutively, making a total of 12 weeks.

She said that Ng's depression did not amount to an impulsive control disorder and would not be considered as a mitigating factor in his favour.

She said the appropriate sentence would be a custodial one after saying she was not inclined to call for a mandatory treatment order as suggested by Ng's lawyer Tan Hee Joek.

"There are too many of these cases prevailing in these courts,'' she said.

Ng could have been jailed for up to one year and fined for insulting the modesty of a woman.