The mug shots, released over the weekend, were altered in photoshop to reduce the appearance of injuries, the BBC reported.
A prosecutor in the case of four young men arrested on suspicion of robbing a bank has ordered an investigation to discover if the suspects were injured in heavy-handed police action, or if they were hurt while resisting arrest, as the police claim.
Public Order Minister Nikos Dendias said in a public conference it was to done to make them more recognizable to the public in order to obtain further information, but rights groups have accused police of brutality in the past.
"The Greek authorities cannot just Photoshop their problems away, said Marek Marczynski, deputy director of Amnesty International's Europe and Central Asia Programme. "This culture of impunity needs to be stopped."
Photos published in Greek media showed the men, all between 20 and 25 and from the Northern town of Kozani, bleeding and bruised far worse than their mugshots later showed.