Grant, alongside Harry and others, was suing News Group Newspapers (NGN) for alleged widespread unlawful information gathering, including landline tapping, burglary and "blagging" confidential information about him.

Grant's case was one of several eligible to go to trial at London's High Court in January, but the actor said he had reluctantly settled with NGN because he could be left with a multimillion pound legal bill if he rejected their offer now, even if he later won the lawsuit.

"News Group are claiming they are entirely innocent of the things I had accused the Sun of doing," Grant posted on X, formerly Twitter, on Wednesday.

"As is common with entirely innocent people, they are offering me an enormous sum of money to keep this matter out of court."

The Love Actually star said Murdoch's lawyers are "very expensive".

"So even if every allegation is proven in court, I would still be liable for something approaching 10 million pounds ($A19 million) in costs. I'm afraid I am shying at that fence."

David Sherborne, the lawyer for both Grant and Prince Harry, told a hearing at the High Court in London on Wednesday that the prince and other claimants also face a similar predicament and have settlements "forced" upon them.

"The Duke of Sussex is subject to the same issues that (actor) Sienna Miller and Hugh Grant have been subject to, which is that offers are made (which) make it impossible for them to go ahead," Sherborne said.

NGN said the settlement with Grant was "in both parties' financial interests not to progress to a costly trial".

Miller settled a lawsuit against NGN in 2021, which her lawyers said at the time was because of the risk of having to pay millions of pounds in legal fees even if she won.

Grant has become a prominent campaigner on press reform since the phone-hacking scandal emerged more than a decade ago, and had joined forces with Harry in recent years.

He had accused Sun journalists of using private investigators to tap his phone and burgle his house.

Grant's settlement does reduce the chances of NGN facing a trial at all over claims of unlawful information-gathering, although, as Sherborne said, Harry's lawsuit continues.

NGN says the claimants are using the lawsuits as a means to attack the tabloid press and that allegations against current and former staff are "a scurrilous and cynical attack on their integrity".

Australian Associated Press