Johnny Depp’s failed libel action against The Sun newspaper over an article which labelled him a “wife beater” is “immensely damaging” to his career, according to a leading reputation management lawyer.

Mr Justice Nicol dismissed the Pirates Of The Caribbean star’s claim, saying News Group Newspapers (NGN) had proved what was in the article to be “substantially true”.

The blockbuster court case, which was the biggest English libel trial of the 21st century, saw both Mr Depp and ex-wife Amber Heard share deeply personal details about their tempestuous relationship, while the actor answered questions about his drink and drug use.

Mark Stephens, a partner at Howard Kennedy and expert in reputation management, who was not involved in the case, told the PA news agency: “I thought this was an ill-advised action anyway, and it’s just proven to be that.

“Obviously there are serious findings of fact against Johnny Depp, that the judge believes that he was a wife beater, that he was a habitual user of drugs and alcohol and obviously one hopes that he gets the help that he obviously needs.

“But I think that the way this case was run is a matter of enormous consternation because Amber Heard was tried against all of the tropes that he used against women, she was alleged to have had affairs, as if that in some way warranted abuse.

“She was said to be a gold digger even though she has already had her settlement from Depp and given all the money to charity because she thought it was dirty money.

“She was accused of making an elaborate hoax which has been said to be false. So I think the way in which she was secondarily abused in the courtroom is an issue which will be studied for years to come.”

Mr Depp has starred in five Pirate Of The Caribbean films and also appears in the Fantastic Beasts films.

Discussing the impact this will have on his career, Mr Stephens said: “It’s immensely damaging.

“This is something which could have been dealt with quietly out of the public spotlight.

“People at the break-up of a relationship never show themselves off to the best advantage but this was obviously a toxic relationship and it was obviously something which would have been better for both parties not to have had it unpicked in public.

“I think it is something he could have chalked up to his bad boy image and moved on but he has drawn attention to two things – one, his demons and his monster, which effectively the judge finds is when he abused Amber Heard, and also the amount of drugs that he’s taking.

“So one of the challenges on the drugs is that although he’s not got a conviction, there are many countries of the world which do not let people who are users of drugs into the country. He will find great difficulty in getting visas for Singapore or Malaysia or countries of that kind.”

Asked if there is a way Mr Depp might be able to recover, he said: “I think the only way he recovers is by admitting the problems that he obviously has and getting treatment, then I think Hollywood and the public will forgive him.

“But it’s very difficult to see how children’s authors like JK Rowling or children’s entertainment companies like Disney can continue to promote somebody who is a wife-beating drug addict and that I think is going to be the problem that he has to deal with.

“I said right at the beginning that is what he was gambling with and he didn’t need to do it, this is another example of self-destruction.”