The hotel backs onto Hospital Lane, with the police station on the opposite side of the road.
It happened at around 3pm on Monday.
A white man, with white hair, wearing a black coat, white t-shirt and black trousers was seen walking near St Julians Avenue with the box over his right shoulder.
If you have any information contact PC 94 Dan Hopkins on 222 222 or call Crimestoppers, anonymously, on 0800 555 111.
