The leak developed by the Navy’s future flagship less than a month after it was officially commissioned by the Queen, is so serious that the ship may need to go back into dry dock and cost millions to repair, The Telegraph wrote.
"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,” a Navy spokesman said.
He added that the ship is scheduled for repair and the fault does not prevent it from sailing again early next year.
Based in Portsmouth, England, the vessel will ultimately be joined by the Prince of Wales, of the same class, currently under construction.
News of the leak came shortly after MPs voiced concerns over the costs of the F35 jet aircraft to fly off the carrier with each plane expected to cost more than £150 million pounds ($200.7 million).
Britain plans to buy 48 F-35 jets by 2025 from US giant Lockheed Martin.