On Thursday police alerted the public to the risk of food being poisoned, saying a blackmailer was demanding millions of euros in cash.
Earlier this month, police received an emailed threat to distribute 20 types of poisoned foodstuffs into supermarkets across Germany and overseas if they did not pay a sum believed to top €10 million ($12 million).
Employees of a drugstore in Peine, about 500 kilometers (320 miles) north of Friedrichshafen in the state of Lower Saxony, said they saw a man similar to the presumed suspect.
On Saturday, police said they found the rest of the poison used to taint the five baby food bottles at the man's house.
In Friedrichshafen, southern Germany, baby food jars containing ethylene glycol, the main ingredient of the antifreeze, were found. Poisoning with this substance leads to an urgent condition that requires rapid medical intervention. According to a report by the BBC, no injuries were reported relating to the poisoned food.
While police believe they do have the suspect in custody, there was reportedly no confirmation that it was the man pictured in the surveillance images.
"We are taking the threat very seriously", Uwe Stuermer, deputy chief of police in the southern lakeside city of Konstanz, told a news conference.
A manhunt has been launched in Germany and in neighboring countries for the suspect, believed to be a white male about 50 years old, who was seen on surveillance camera wearing glasses and a white hat.
German officials did not release the names of the food stores that had been targeted but did say there was no reason for the public to panic.