Carol Marlow, President of Cunard, the ship's owners, said the company had received "certain information" and had acted upon it by increasing security surrounding the 67 000-ton vessel.
"We take these sorts of things very seriously and, while we do not actually believe there is any cause for alarm, we have put the ship on a higher level of security," she said.
Marlow stressed that Cunard was working with the Egyptian authorities and said that shore security had also been increased.
"All our excursions from the QE2 are going ahead as planned," she added.
Send instant messages to your online friends http://uk.messenger.yahoo.com