Two teenagers, who allegedly transmitted obscene materials in messaging application Telegram, were taken back to court yesterday and handed an additional charge each.
Abdillah Sabaruddin, 17, and Justin Lee Han Shi, 19, are now also accused of having obscene materials on their electronic devices, such as mobile phones.
Court documents did not reveal what these materials were.
The two teenagers are accused of committing the offences earlier this month. They were among four people who were first taken to court on Tuesday.
In an earlier statement, the police said that the four alleged offenders were caught for their "suspected involvement in circulating obscene materials and promoting vice activities" through a chat group called SG Nasi Lemak.
The others are: Leonard Teo Min Xuan, 26, and Liong Tianwei, 37.
All four were then charged with one count of transmitting obscene materials by electronic means.
Lee, Teo and Liong are accused of committing the offence between January and this month.
The number of members exceeded this figure when the SG Nasi Lemak chat group was still active.
The "entry fee" to the chat group.
Abdillah allegedly transmitted an explicit picture of two naked women to SG Nasi Lemak on Oct 5.
The police had received several reports against the chat group between March 15 and Oct 3.
Officers from Ang Mo Kio Police Division managed to establish the identities of the four alleged offenders and arrested them at various locations islandwide on Monday.
More than 10 electronic devices, including a central processing unit, a laptop, a hard disk and several mobile phones, were seized as case exhibits.
Reports earlier this month said that the chat group was used as a platform for sharing obscene photos and videos of Singaporean girls.
The photos are said to include upskirt images.
Screenshots of the chat group suggest that it had more than 44,000 members when it was still active.
According to Chinese evening daily Lianhe Wanbao, the chat group was set up more than a year ago, but its membership numbers spiked in recent months with more people becoming aware of it. They had to pay $30 as an "entry fee".
The two teenagers were each offered bail of $5,000 yesterday and their cases have been adjourned to Nov 15.
Liong and Teo will be back in court next Tuesday.
Offenders convicted of transmitting obscene materials by electronic means can be jailed for up to three months and fined.