Officers from the special antiquities squad seized dozens of complete pots, as well as a rare bronze double ax and four marble column bases, police said.
Several of the antiquities had been on public display, built into the bar's walls, police said. They did not provide dating for the artifacts, but said most appeared to have been fished out of the sea.
The bar owner was not arrested as archaeologists tried to establish whether certain of the antiquities had been declared to authorities, police said.
Under Greek law, all antiquities found in the country are state property. But sometimes individuals are allowed to retain artifacts after registering them with authorities, according to the AP.