The 45-year-old owner of a transport company was sentenced to 32 years in prison and 24 strokes of the cane in April last year for repeatedly raping his daughters. He has 10 wives and 64 children.
The man, a Muslim who conducted religious classes for his family, told some of his wives and daughters during one class in March 2004 that the Muslim holy book, the Quran, said he owned his children and could have sex with them.
The wives then acted as his messengers, notifying the girls - then between 12 and 15 years old - whenever the man wanted to have sex. He was arrested in June 2005 after the eldest daughter notified police, the court documents said.
Two of the wives were sentenced Wednesday to three years in jail after pleading guilty to charges of abetting incest over an 18-month period from December 2003. The other wife was sentenced to nine years because she played a more active role.
"Instead of acting to prevent their daughters from falling prey to the sexual perversity, they meekly surrendered their maternal instinct and duty to protect their daughters," District Judge Shaiffudin Saruwan said in his judgment.
The judge ordered the names of the man and his wives to be withheld to protect his daughters' identities.
The man has 33 sons and 31 daughters between 9 months and 16 years of age. He had four lawful wives under Muslim law, while the other wives were "contractual" - an arrangement in which a Muslim couple enters into a union for a fixed term.
Singapore law allows Muslim men to have four wives. Contractual marriages, however, are not recognized and are invalid.
All of the three sentenced wives were legal wives.
The choice of the city of Helsinki is not incidental as the capital of Finland had hosted US-Soviet negotiations on the limitation of nuclear stockpiles in 1969