The missing person has been identified as 27-year-old Brazilian national Mateus Rodrigues Muniz Da Silva.
An alert was issued by the Royal Gibraltar Police seeking the public’s help in locating the man who was seen for the last time on Saturday, just after 11 am disembarking the liner at Port Gibraltar.
Local authorities released the man's photo saying there was no description of the clothes he was wearing at the time.
The police didn't mention if he was a crew or a guest/passenger.
Mein Schiff Herz had to leave the port on Saturday at 3 pm.
For more Mein Schiff Herz incidents and accidents see the ship's CruiseMinus page.