LONDON -- A faulty shaft seal has been identified in the British Navy's newest and most expensive aircraft carrier HMS Queen Elizabeth during sea trials.

Media reports in London said details were revealed just days after Queen Elizabeth commissioned the largest ship ever built for the Royal Navy, the $4.15 billion HMS Queen Elizabeth.

A British Royal Navy spokesman said, "An issue with a shaft seal has been identified during HMS Queen Elizabeth's sea trials. This is scheduled for repair while she is alongside at Portsmouth. It does not prevent her from sailing again and her sea trials program will not be affected."

British Defense Secretary Gavin Williamson said the cost of repairs will be funded by the contractors that built HMS Queen Elizabeth, adding that "this is the reason why we have the sea trials, to make sure that everything is working absolutely perfectly."

A spokesman for British engineering companies BAE Systems, the ship builders, said, "It is normal practice for a volume of work and defect resolution to continue following vessel acceptance. This will be completed prior to the nation's flagship re-commencing her program at sea in 2018."

The BBC's defense correspondent said, "It is clearly embarrassing. They have known about the problem for some time but they did not want it to get in the way of the commissioning ceremony in front of the Queen."