A father of four has been arrested for selling his youngest daughter for 28,000 yuan ($4,627) so he could afford a second son, Minhang district police said Tuesday.

Police have detained the suspect, surnamed Wang, from Guizhou Province, pending charges for child trafficking, according to a press release from the Minhang District Public Security Bureau.

The child has been returned to her family, said a press officer surnamed Xue from the Minhang District Public Security Bureau.

Wang and his wife, surnamed Li, who were married in 2007, already had three daughters and a son, police said.

However, Wang insisted on having another son because of a tradition in his hometown that favors families that have at least two sons, Xue said.

As migrant workers, the couple already had trouble supporting their four children, Xue said.

With Li pregnant with their fifth child, Wang decided he could spare a daughter so he could afford to raise a second son. He convinced Li that they should sell their infant daughter to an infertile couple he found in Yancheng, Jiangsu Province.

To explain why his daughter disappeared, Wang told his wife to file a false police report claiming that the girl had been abducted, police said.

Li went to a police station in Minhang district on January 19 and reported that a stranger had abducted her daughter near Tonghai Road. She said that a stranger had somehow drugged her after approaching her on the street to chat. She claimed she fell unconscious after the stranger patted her on the shoulder.

Police didn't buy her story, noting that it was nearly impossible to drug someone into unconsciousness with just a pat on the shoulder.

After talking with police, Li admitted that she and her husband had actually sold their daughter.

A team of police officers searched for the girl in Jiangsu Province and returned her to Shanghai a day later, according to the press release.

Li was released on bail because she was pregnant and someone needed to look after her children.