Maritime and Coastguard Agency surveyors visited the 59,000 tonne MSC Opera on its arrival at Southampton on Wednesday to undertake a routine port state control inspection.
A spokesman said: “Various defects were found which meant that the ship was not fully compliant with international maritime safety regulations.
“As a consequence the Maritime and Coastguard Agency decided that it was necessary to detain the vessel in Southampton until such time as the owners were able to demonstrate compliance. Maritime and Coastguard Agency surveyors have made a number of follow-up visits to the ship to assess progress although the ship continues to be detained at this time.”
The Opera was due to leave Southampton at 4pm on Friday for an eight-day cruise to the Norwegian fjords.
But a spokeswoman for MSC said yesterday it “was not true” the vessel had been detained.
A Maritime and Coastguard Agency spokeswoman said the vessel’s owners had been given a solution that allowed them to meet the agency’s requirements.
The ship was eventually allowed to sail at 7pm, just three hours later than scheduled.
Earlier this month, the MSC Opera broke down and had to be towed into a Swedish port after developing technical problems in the Baltic. The ship lost all electrical power off the island of Gotland, stranding around 400 British passengers on a trip taking in Copenhagen, Helsinki and St Petersburg.
This summer MSC Opera is offering cruises to Amsterdam, France and Spain as well as the Norwegians fjords and the Baltic operating from Southampton.