Jürg Bürgin, 40, had been placed in remand on Wednesday after being charged in a district court, along with 47 other men, for allegedly paying a 17-year-old Singaporean callgirl for sex in late 2010 and early 2011.
Bürgin quit Swiss banking giant UBS earlier this year as a mid-level executive before the scandal erupted, banking industry sources said.
UBS has refused to comment on his case.
Lawyer Selva Naidu declined to disclose the identity of the person who posted Bürgin's Sg$15,000 ($12,000) bail.
"As matters stand, he is not pleading guilty," the lawyer told AFP.
Singapore law makes it illegal for anyone to pay for the sexual services of a woman under the age of 18. The offence is punishable by up to seven years in prison, a fine, or both.
Bürgin's case will be heard in court on June 18th.
Most of the accused are Singaporeans ranging from their 20s to their late 40s. They include businessmen, a former school principal, a navy captain and a police superintendent.
The girl's services were advertised on a website that has been shut down. Her identity is being kept secret on orders of the court.