The discovery of a leaflet has led to a couple in Sichuan province being reunited with their son, who was taken away three decades ago because of the family planning policy.

"I'm so overwhelmed with excitement. I didn't expect it to be true, but my son has returned after so many years," said 59-year-old Zou Yuhua, who gave birth to a second son in 1983.

Six months later, government workers and police-men visited Zou in Wolong village, Laojunjing township, and took away her baby.

The family-planning policy was strictly enforced in Sichuan province because it had a population of more than 100 million before its largest city, Chongqing, became a municipality in 1997.

Wu Taizhang, who was Party chief of Laojunjing township at the time, said that if a villager gave birth to a second child, it would be taken away and given to a couple without children.

After their son was taken away, Zou and her husband Zhang Mingfa learned that he had been given to a family in Jinyu township. Zhang tried to visit a single man surnamed Wang who had adopted a son similar in age to his own, but he was driven away by people from the township.

In 1997, however, Wang took a 14-year-old boy to Zhang's home, saying he must be their son and that he could no longer afford to support him.

"We sent the boy to school. We sent him to a driver's training school after he left the army. We bought him a small truck after he got a driver's license. But in 2006, he left after he learned we were not his biological parents, and we had adopted him by mistake," Zou said.

However, it was a leaflet distributed by their own son, Zhang Huayong, that led the couple to him.

He had been adopted by a couple more than 40 kilometers away. When he was 4, his adopted parents told him he was given to them by the Jianyang county family planning bureau.

But when he got older, he decided to look for his biological parents. In late November, he had 50,000 leaflets printed with information about his own parents.

Only five days after he started distributing them, a neighbor of his biological parents received one and showed it to the couple.

They met soon after Zou called him, and a paternity test showed she was his biological mother.

"I'm so overjoyed to have found my own parents," the son said.

"My parents have under-gone many hardships since they lost me as a child. I will repay them," he said.