(CNN) -- Twin newborn girls allegedly stolen by a maternity doctor in a baby trafficking scandal in northwest China were returned to their parents over the weekend.
Surrounded by reporters and photographers, police handed the two infants back to their parents at Fuping County Hospital in Shaanxi province late on Saturday. The twins' father, Qi Kunfeng, presented a banner to thank police for recovering the babies, while their mother, Wang Yanyan, wept.
"They're all healthy and well. I just hope we can live happily together as a family ever after," Qi told CNN by telephone on Monday.
"It's a big surprise for my wife. She can't eat and sleep well because of over excitement."
The twins were allegedly separated and sold to two families by a doctor named Zhang Shuxia, the deputy director of the maternity department in the Maternal and Child Health Care Hospital in Fuping County.
Zhang had told the parents that the twins had serious health issues and persuaded them to give them up after their birth on May 29.
"The doctor was pretending to be very anxious, telling me that my babies have congenital problems. She said the twins would be brain damaged or paralyzed," said the mother.
She never saw her children after the birth: "I insisted on seeing the babies, but she wouldn't let me," said Wang.
The new parents trusted Zhang: "I never suspected that she was selling my babies, because she was a family friend," she said.
The twins' father told CNN that the loss of the children had a profound impact on the couple.
"Every night for two months my wife would cry, and she couldn't eat from worry."
Of Zhang, his former friend, he said: "I think she is evil. She is a terrible person."
"We trusted her so much. How could she be so cruel to sell our babies?"
Since news of the scandal broke last week, police have received reports of 55 similar cases from local residents, including 26 cases pointing to Zhang, the China Daily reported.
Zhang has been detained along with eight other suspects on suspicion of trafficking.
Three babies have been rescued, including the twins. A baby boy was reunited with his parents last week after allegedly being sold by the same obstetrician to traffickers.
CNN's David McKenzie and Zhang Dayu reported from Shaanxi, China. Journalist Katie Hunt wrote from Hong Kong