The 45-year-old man, who cannot be named in order to protect the identity of his daughters, was sentenced on Tuesday after he pleaded guilty to five charges of rape and admitted to another 34 charges, including rape and attempted aggravated rape.
"The numerous rapes in this case were systematic and sickening," said High Court Judge Tay Yong Kwang in the judgment.
"The mothers of the young girls had somehow been persuaded by the accused that what he was doing was right. That deprived the daughters of one escape route that they could have taken -- that of approaching some adults whom they trusted to confide in them their predicament."
The court sentenced him to 24 strokes of the cane.
According to the court documents, the man said he was a qualified religious teacher. During a religious class, he told his wives and daughters that, according to the Koran, he had complete ownership over his children as a father, including the right to have sex with them.
The wives then acted as his messengers, telling their daughters to meet their father in his bedroom whenever he wanted sex over a period of 18 months.
Two of the teenage daughters became pregnant and had to have abortions. The eldest daughter, who is now 16, went to the police last June to report the rapes.
In his mitigation plea, the man said he had found his older daughters "behaving inappropriately" with boys and he thought that "if he could satisfy the sexual needs of his daughters, they would be less likely to engage in sexual activities with boys".
The man, who ran a transportation business, had four legal wives and six contractual wives -- an arrangement whereby a Muslim couple enters into a union for a fixed term. His 33 sons and 31 daughters range in age from 9 months to 16 years.
Singapore's multiracial population is about 77 percent ethnic Chinese, 14 percent Malay, 8 percent Indian, and 1 percent Eurasian. Muslims are allowed to have a maximum of four wives. Contractual marriages are not recognized and are invalid.
