After a sweep spanning seven provinces and on a special order from Beijing, Chinese police have arrested 13 baby-snatchers and rescued five toddlers they had kidnapped to sell.

The abduction and sale of children can be a crime punishable by death in China, but this fails to deter hundreds each year who are eager to profit from the desperation of parents anxious for a son and hindered by a strict “one-couple, one child” family planning policy.

Boys fetch a higher price than girls, but both are sought after. The cost of a baby can differ from province to province from as little as £50 for a boy in poor southwestern Yunnan province to several hundred pounds further north and in more developed coastal regions.

The latest rash of baby-kidnappings was reported in central Hubei province in urban areas where many poor farmers move in search of better-paying jobs in brick kilns and small factories and often take their children with them. The children were sold for between 860 yuan (£86) and 26,000 yuan (£2,600).

Police began to receive reports in September of two men on a motorcycle who grabbed toddlers as they played in the street – some in broad daylight and with sight of their parents. The first to disappear was a two-year-old girl. Then on November 14 a two-year-old boy vanished off the street. A two-year-old girl snatched on December 9 was finally dumped on the street after family and friends gave chase. But five days later a three-year-old boy was abducted.

Mothers began to stay at home, preventing their children from going to kindergarten. They locked their doors before dark. Even adults stopped speaking to strangers, anxious the abductions could spread. After all, women have for many years been targets of gangs who sell them to men, usually farmers in remote regions, who have failed to find a wife.

The Ministry of Public Security in Beijing ordered a special task force to handle the case and soon local police were carrying out house-to-house searches of migrant workers in this area of Hubei province. They soon came up with leads and, with clues provided by local residents, they arrested a 21-year-old man from southern Yunnan province on January 5.

After that breakthrough the search spread to several other provinces. In coastal Fujian province, police arrested eight people and recovered three children. The total of arrests involving this particular gang has now risen to 13 with five toddlers recovered – of whom three are being returned to their families.

These children are the lucky ones. They were found quickly. Many are never found. Li Hupeng was not recovered until more than two years after he was snatched while playing in the lane near his parents’ rundown farmhouse. He had already developed an affection for his new family and took months to settle back down with his real parents. Interviewed by The Times, he still retained a little of the dialect of the family in a neighbouring province that had paid his kidnappers 740 pounds to ensure a brother for their three daughters.

International aid workers say many children are bought by coastal families rich enough to pay the fines associated with a second child and who convince the local authorities that they have adopted the infant of a distant relative too poor to raise as their own.