Another mum spotted the man running off in Boxhagener Platz in the German capital Berlin.
Despite having her own two-year-old girl, she chased after the alleged abductor.
The woman, named in local media as Heike S. (name changed), 27, called for help and a kiosk operator named in reports as Zoran Z, 44, came to her aid.
Zoran sprinted after the man and caught up with him, with a witness filming the confrontation on their phone.
Zoran said: “I asked him: ‘Is this your child?'”
The suspect responded: “No. I love children. I can’t understand how mothers and fathers leave their children at home with some caregivers.”
He can be seen holding the girl firmly on his shoulders in the images.
Zoran managed to convince the man to take the child back to the playground.
As they were walking back towards the playground, Zoran asked the suspect: “Why did you take the child with you?”
The suspected kidnapper answered: “I think children are simply the most important thing. Children are our future, aren’t they?”
When they arrive at the playground in the park, he asks the girl on his shoulders: “Is your mum here in the park?”
He added: “All right, that’s where we’re going, right? We’re going to mum, right? You sit up there. You have to look for where she is. You have the best view, OK? Where’s mum? Oh, damn, a lot of people. We have to look closely.”
A crowd of people had formed in the playground, with concerned parents surrounding the distraught mum.
Zoran later told local media: “The mother was panicked. Another mother was already on the phone with the police. The guy then put the child in her arms. She was probably in such a state of shock that she spoke to him normally.”
Arriving police officers finally arrested the suspected kidnapper.
The 44-year-old was known to the police and was drunk.
Because he refused to take a breathalyser test, a blood sample was ordered.
A police spokesman told local media: “After the arrest, the suspect was taken into police custody and was processed for identification. At the time, the conditions for issuing an arrest warrant were not met, which is why he had to be released.”
The police forwarded the investigation to those responsible for child offences on suspicion of kidnapping.
They found that there was no evidence that he was a paedophile.
Officers determined the suspect had a permanent residence, that there was no risk of escape, and that he had a mental disorder.
The police, trying to reassure worried parents on Twitter, said: “So far there is no evidence of a sexual motivation or of malicious intent. Visiting a playground in Berlin is no more dangerous than usual.”
Heike S. was quoted in local media as saying: “I imagined what would it have been like if it had been my child. Now I also know that he is back. That he can stand in front of us again at any time.
“That he might recognise me and my daughter. Why didn’t the police put up a notice at the playground? That is scary.”
Another mum, named in local media as Anne-Marei Heinrich, put a warning up on the gate.
The mum-of-two is also worried that the perpetrator could soon be back at the playground.