A man who allegedly protested against the judiciary, claiming miscarriage of justice, was hauled to court yesterday for offences under the Public Order Act.

Yan Jun, a 40-year-old Singaporean, had allegedly displayed two placards, including one in Chinese which read, "Protest against High Court of Singapore for miscarriage of justice".

Yan, who is accused of taking part in an assembly which he knew was prohibited, allegedly did this at Istana Park at 10.02am on March 2.

The second charge accuses him of taking part in a public assembly without a permit by displaying the same placards at High Street Centre in North Bridge Road on Wednesday at about 4.25pm. He was arrested.

Deputy Public Prosecutor Yang Ziliang said Yan might have a mental disorder, such as persecutory delusional disorder, and applied for Yan to be examined at the Institute of Mental Health (IMH).

Stating his two defences, Yan said Istana Park was a public park and not "prohibited''. He accused the police of being "corrupt'' in handling his application for a protest permit.

When Yan objected to his remand at IMH, DPP Yang said the grounds for the application had been fully set out. The way Yan talked about his defence suggested there might be something preventing him from accepting and processing information critical to his understanding of the nature and consequences of his action, said the DPP.

The judge ordered Yan to be remanded at IMH. He told Yan he is entitled to engage a lawyer later.

Yan will appear in court again on April 28. If convicted, he could be fined up to $5,000 on the first charge, and up to $3,000 on the second.