The policeman in civilian clothing had spotted the thief as he tried to sneakily pull out the wallet from the back pocket of his trousers.
He had grabbed hold of his hand but the thief ran off the U6 train at Westbahnhof station.
He was stealthily followed by the officer, who spotted him at the station already targeting his next victims.
The policeman watched as he tried again to get hold of someone's purse and then went in and arrested the man in front of numerous bystanders.
The suspect was reported for theft but since he is only accused of two attempts of theft he was allowed to go free for the time being, according to a police spokesperson