Johnny Depp case: What are the libel laws and how do they work?

Amber Heard and Johnny Depp were married in February 2015

After weeks of revelations and accusations in court about his personal relationships, actor Johnny Depp's mammoth legal action against The Sun for libel is coming to an end - with a judgement expected at the end of the summer.

But what are the libel laws and how do they work?

What is libel?

Libel is part of the law of defamation. It's a way of asking the courts to protect our reputation if we feel we have been wronged by something that has been published in permanent form. If the defamatory words have merely been said in public, that's known as slander.

Mr Depp says that The Sun libelled him because it published an article that was defamatory. The article said he was a "wife beater" amid allegations about his relationship with his former wife, Amber Heard.

He says that has caused enormous damage to his reputation - which ultimately will cause him losses in his career and life.

Is this a law to protect celebrities?

Defamation court battles can be very expensive - but anyone who thinks they have been defamed can sue.

Companies, like individuals, have reputations to defend - so they too can go to court.

How can Johnny Depp sue when he lives in Los Angeles?

It doesn't matter that he lives in the US.

The key fact in the case is that the alleged defamation was published in the UK, where he has a reputation too that he says has been seriously harmed.

• Depp's lawyers say video shows Amber Heard 'attacked' sister

• Depp legal case against The Sun gets go-ahead from judge

Does the law of defamation apply to what I say online?

Absolutely. Anything that you publish openly on social media that is allegedly wrong and harmful to another person or company could end up being very expensive.

Coleen Rooney (L) and Rebekah Vardy are involved in a legal dispute

One well-known current example of an online defamation case is the so-called "Wagatha Christie" row between two wives of top footballers.

Rebekah Vardy (married to Leicester's Jamie Vardy) has recently commenced a libel action claiming Colleen Rooney (married to former England captain, Wayne Rooney) falsely accused her on Instagram of giving journalists stories about her private life.

What's The Sun's defence in the Johnny Depp case?

Defamation law is slightly different between England and Scotland but, in general terms, the onus is on the party who is accused of damaging someone's reputation to defend the words they used.

In England, there are five ways that someone can see off the claim in court:

• Truth: The meaning of the words are factually accurate and cannot be disproved. This is The Sun's defence against Mr Depp - the newspaper has sought to prove that the allegation that Mr Depp is a "wife beater" is justified. In Scotland this defence is called "veritas".

• Honest opinion: That the words are an honestly-held opinion, based on an analysis of facts, that anyone else could also hold. This defence is very important to people like professional film or theatre reviewers, who can be accused of unfairly criticising productions. In Scotland this defence is called "fair comment".

• Privilege: This protects the accurate and fair reporting of what is said in the courts and Parliament, among other official bodies, without fear of being taken to court.

• Innocent dissemination: This protects TV channels and radio stations from being sued when a contributor, such as a phone-in guest, unexpectedly shouts out something highly defamatory.

• Responsible publication: This allows journalists to argue that even if the facts that they published weren't entirely correct, they were reporting something that was clearly in the public interest. This is a significant difference to the position in Scotland, where the legal test means it is harder for a journalist to prove that the story was in the public interest.

Can anyone sue, at any time?

If someone believes they have been defamed in England, they have to begin their case within a year of the publication.

In Scotland it's three years - but with a twist. If the article or comment was published online, the three-year clock starts ticking from the last download. Critics say this means there's no deadline at all, and therefore the law is unfair to journalists.

So how do libel cases end?

In four ways:

• The person who says they have been harmed accepts an apology or public clarification, long before the matter ends up in front of a judge.

• The legal action begins - but when it becomes clear that the case is going against the publisher, they offer to settle with a statement in court acknowledging they were wrong. There is often a compensation payment.

• The case goes to full trial. There will be enormous legal costs for both sides and, if the publisher loses, a potentially huge compensation pay-out.

• The person who says they've been wronged realises they can't afford the risk of losing - so they give up.