In 1997, the then two-year-old Guo Xinzhen was abducted by a woman near her home in eastern China.
DNA, blood and other evidence were secured at the site - but the technology of the time had its limitations and the case remained unsolved.
But the police did not give up hope.
Neither did the boy's father Guo Gangtang.
On a motorcycle full of leaflets and a flag with a picture of his son, he traveled through all the provinces of China in search of tracks.
Reunited
According to the state news agency Xinhau, he traveled a total of 500,000 kilometers and harvested ten motorcycles, all his savings and even got into financial debt during his search for his son, which he never found.
However, he managed to track down over 100 kidnapped children and reunite them with their parents.
Now, 24 years later, Guo Gangtang has met his missing son again.
On Monday, the family was reunited in Liaocheng.
Traced with DNA
The case was never closed and according to Chinese police, the authorities found a new clue earlier this year.
Using DNA analysis and facial recognition, the clues pointed to a 26-year-old man in Henan.
After a DNA test, it turned out to be the kidnapped Guo Xinzhen.
Two people, a man and a woman, have now been arrested on suspicion of kidnapping.
Police say that they both in interrogation have told that the woman took Guo Xinzhen away from his home in 1997. Then the then couple met up in Henan and sold the boy.
It is unknown at this time what he will do after leaving the post.
Became a movie
The father's journey in the search for his son resulted in 2015 in the film "Lost and Love".
It is estimated that tens of thousands of children are abducted in China every year and according to the US authorities against trafficking, the country is ranked number three in the world.
China is now said to be working to overcome the problem and has, among other things, introduced a national DNA database to trace missing children. More than 4,700 children are said to have been found using the method, Xinhau states.