I think, Paul, you're referring to the Costa Allegra which sadly has recently arrived in Turkey for scrapping. Built as cargo ships in Finland in 1969, she and her sister Costa Marina were originally called Annie Johnson and Axel Johnson .
After conversion they were operated by a number of companies and the former Costa Marina now sails for a Korean operator under the name Club Harmony.
They've both visited Dover under the Costa flag.
The demise of the Costa Allegra seems to have been the result of a serious fire in February, just six weeks after the Costa Concordia debacle.
Here's the Costa Allegra at Dover in 2005.