They were each fined $2,000 yesterday, the maximum fine for an obscene act.

Court papers state that Eng Kai Er, 24, and Jan Philip, a 21-year-old Swede, did what they did 'to seek thrill'.

On Thursday, the pair were bashful and kept their faces hidden from photographers, like they did before a court appearance last month.

Eng, a Singaporean, was in a black skirt suit and cap, sunglasses and a face mask; Philip was in a full suit with tie.

Eng, who is on a scholarship from the Agency for Science, Technology and Research (A*Star) to pursue a biomedical science course at Karolinska Institutet in Sweden, was heard saying to photographers from behind her mask: 'You won't get anything.'

Their behaviour yesterday was in stark contrast to that in January, when they walked down Lorong Mambong on a busy Saturday evening, waving nonchalantly to gaping onlookers.

In mitigation, their lawyer William Chan said they did try to check whether public nudity was an offence before pulling their stunt.

Philip, an exchange student at the National University of Singapore, looked up the Penal Code, which said obscene acts were illegal.

What he did not realise, however, was that public nudity was considered obscene and hence was an offence.

Read the full story in The Straits Times today.