Britain's biggest ever warship, the new STG3.1 billion ($A5.4 billion) aircraft carrier HMS Queen Elizabeth, has a leak and needs repairs, the Ministry of Defence says.
The 65,000-tonne ship, hailed as Britain's most advanced military vessel and which was only officially commissioned by the Queen two weeks ago, has an issue with a shaft seal which was identified during sea trials, the ministry said on Tuesday.
"This is scheduled for repair while she is alongside at Portsmouth," a Royal Navy spokesman said. "It does not prevent her from sailing again and her sea trials program will not be affected."
The Sun newspaper reported that the 280-metre warship, the nation's future flagship vessel, was letting in 200 litres of water every hour and the fix would cost millions of pounds.
A defence source said the navy was aware the ship, which took eight years to build, had an issue when it was handed over by manufacturers and the Sun said the builders would have to foot the repair bill.
The Aircraft Carrier Alliance - a consortium including British engineering companies BAE Systems and Babcock , and the UK division of France's Thales - built the Queen Elizabeth and its sister aircraft carrier, the HMS Prince of Wales, as apart of a STG6.2 billion ($A10.8 billion) project.
"It's normal practice for a volume of work and defect resolution to continue following vessel acceptance," BAE Systems said in a statement.
"This will be completed prior to the nation's flagship recommencing her program at sea in 2018."
Chris Parry, a former senior Royal Navy officer, said all ships took on water.
"That's why you have pumps," he told Sky News.
"When you get a brand new car not everything's perfect, you have to send it back to the garage to get a few things tweaked. This is exactly in that bracket."
