The Hollywood actor Johnny Depp has lost his high-stakes libel action in the London courts against the Sun after the newspaper described him as a “wife beater”.

The high court dismissed the claim by the Pirates of the Caribbean star for compensation at the end of one of the most widely followed libel trials of the century. His lawyers said he would most likely appeal against the “perverse and bewildering decision”.

In the 129-page ruling, the judge, Mr Justice Nicol, said: “The claimant [Depp] has not succeeded in his action for libel … The defendants [the Sun and News Group Newspapers] have shown that what they published in the meaning which I have held the words to bear was substantially true.

The judge added: “I have found that the great majority of alleged assaults of Ms Heard by Mr Depp have been proved to the civil standard.”

He also said he accepted Heard’s evidence that the allegations she made against Depp “have had a negative effect on her career as an actor and activist”.

“I have reached these conclusions having examined in detail the 14 incidents on which the defendants rely as well as the overarching considerations which the claimant submitted I should take into account. In those circumstances, parliament has said that a defendant has a complete defence.”

The judge said he did not accept Depp’s characterisation of his ex-wife as a gold-digger. “I recognise that there were other elements to the divorce settlement as well,” Nicol noted, “but her donation of … $7m to charity is hardly the act one would expect of a gold-digger”.

In 12 out of the 14 incidents of assault reported by Heard, the judge said he found the allegations proved. “I do not regard [the Sun’s] inability to make good these allegations [in the other two incidents] as of importance in determining whether they have established the substantial truth of the words that they published.”

In his conclusion, Nicol cited an email sent by Depp in August 2016 as indicative of the actor’s true feelings towards Heard. Depp’s message said: “I have no mercy, no fear and not an ounce of emotion or what I once thought was love for this gold digging, low level, dime a dozen, mushy, pointless dangling overused flappy fish market … I can only hope that karma kicks in and takes the gift of breath from her … Sorry man … But NOW I will stop at nothing!!!”

The long-awaited decision was published online at 10am on Monday, more than three months after the high court hearing finished in late July.

Depp, 57, had sued the Sun’s publisher, News Group Newspapers (NGN), and its executive editor, Dan Wootton, over an article published in the Sun that originally carried the headline “Gone Potty: How can JK Rowling be ‘genuinely happy’ casting wife beater Johnny Depp in the new Fantastic Beasts film?”

NGN relied on a defence of truth to the claim. The burden of proof was on the Sun to demonstrate that the story was substantially accurate on the balance of probabilities.

Immediately after the ruling, the publisher issued a statement saying: “The Sun has stood up and campaigned for the victims of domestic abuse for over 20 years. Domestic abuse victims must never be silenced, and we thank the judge for his careful consideration and thank Amber Heard for her courage in giving evidence to the court.”

The US lawyer representing Heard in her forthcoming defamation case on similar grounds in the US, Elaine Charlson Bredehoft, said: “For those of us present for the London high court trial, this decision and judgment are not a surprise.

“Very soon, we will be presenting even more voluminous evidence in the US. We are committed to obtaining justice for Amber Heard in the US court and defending Ms Heard’s right to free speech.”

Jenny Afia, the solicitor at the London law firm of Schillings who represented Depp, said: “This decision is as perverse as it is bewildering. Most troubling is the judge’s reliance on the testimony of Amber Heard, and corresponding disregard of the mountain of counter-evidence from police officers, medical practitioners, her own former assistant, other unchallenged witnesses and an array of documentary evidence which completely undermined the allegations, point by point. All of this was overlooked.

“The judgment is so flawed that it would be ridiculous for Mr Depp not to appeal this decision.”

Although Depp’s lawyers have indicated he is likely to appeal, it may prove difficult for them to overturn what are findings of fact by the trial judge. The judge’s rulings on those points are effectively similar to a jury’s verdict in a crown court. Appeals are more normally on points of law.

Commenting on the decision, Caroline Kean, a partner at the London law firm Wiggin LLP, said: “This is a heartening and just decision which serves as a reminder that British libel laws are not there to curtail free speech and the media’s right to publish on stories of global interest.

“This case was effectively a forum for two private individuals to slug it out and a clear misuse of taxpayers’ money, taking up court resources that could have been deployed for more worthy causes.”

Emily Cox, a partner at the London law firm Stewarts, which specialises in libel cases, said: “Although not a criminal determination of guilt, it is difficult to see how Depp will ever be able to shake off the ‘wife beater’ label now, personally and professionally. The judge expressly endorsed the notion that Depp had a ‘monster side’ and held that he did assault Heard and put her ‘in fear of her life’.”

Lisa King, the director of communications and external relations at the domestic violence charity Refuge, said: “This is an important ruling and one which we hope sends a very powerful message: every single survivor of domestic abuse should be listened to and should be heard. No survivor should ever have her voice silenced.

“A common tactic used by perpetrators of domestic abuse is to repeatedly tell victims that no one will believe them – and to use power and control to try and silence them. What we have seen today is that power, fame and financial resources cannot be used to silence women. That is a welcome message for survivors of domestic abuse around the world.

“We stand in solidarity with Amber Heard, who has shown immense bravery in speaking up and speaking out.”