An extensive search was carried out on the aircraft.
A Ryanair flight that departed from Dublin made an emergency landing in Berlin during a flight to Poland on Sunday night.
German police released no further details about the emergency landing but German media reported it was due to a bomb threat.
German newspaper
Bild Zeitung reported that the flight landed in Germany around 8pm on Sunday evening.
It said passengers were removed from the aircraft and were put on a different plane which finally left the airport in the early hours of Monday morning.
Following an extensive search of all passengers and baggage, nothing was found on the aircraft and it is due to fly back to Ireland on Monday.
Berlin police confirmed that officers had completed their security checks "without any danger being detected".
In a statement, Ryanair apologised to passengers for the "unavoidable delay, which was outside the airline's control".
It added: "The crew on a Ryanair flight from Dublin to Krakow FR1901 yesterday were notified by German ATC of a potential security threat on board. The captain followed procedures and diverted to the nearest airport, Berlin.
"The aircraft landed safely and passengers were offloaded to facilitate extensive security checks of passengers and all baggage.
"Once cleared by German authorities, passengers travelled onwards to Krakow on a spare Ryanair aircraft after a delay on the ground of approximately seven hours."
