Two Chinese tourists were arrested in Berlin for making Hitler salutes outside the German parliament on Saturday.
Criminal proceedings have been started against the middle-aged men for using symbols from a banned organisation.
The pair have been released on bail of €500 (£450; $600) each.
Germany has strict laws on hate speech and symbols linked to Hitler and the Nazis.
The men - aged 36 and 49 - could face a fine or a prison sentence of up to three years, according to police.
The same charges are most commonly used to prosecute members of the far right.
A police spokeswoman told AFP news agency that the men could leave the country during the investigation and that if a fine is handed down, the bail money they had already paid would probably cover it.
The visitors were seen taking pictures of each other with their mobile phones outside the Reichstag building, which houses the German parliament.