Johnny Depp's various court antics – including doodling and snacking on gummy bears – could "jeopardise" his defamation trial against Amber Heard, legal experts claim. 

The 58-year-old US actor, who is suing his ex-wife for $70 million in a Virginia court, has been filmed at times giggling and drawing pictures during her explosive testimonies, while also refusing to look at her once during her time on the stand. 

During his own cross-examination, Depp also made several snide comments at Heard's lawyers. 

Speaking to Daily Mail, Virginia lawyer Lee Berlik said the Pirates of the Caribbean star could be rubbing the jury up the wrong way by appearing to not take the situation seriously. 

"In a normal case where nobody knows the parties and you have somebody suing his wife for [millions], you don't want to see that person giggling and chuckling to himself and making smart-arse comments on the witness stand," Berlik told the publication. 

"You want the jury to sympathise with your client and they have to be likeable for that. If you're acting like this, it's just fun and games that could turn a lot of people off. 

"But I don't know how Johnny Depp being Johnny Depp changes that. Normal people aren't met by 100 screaming fans as they enter the courtroom. I think it will turn some people on the jury off, but will it turn all of them off?" 

However, another Virginia-based lawyer, Steven Krieger, told the publication that Heard's "deadpan" expression during Depp's testimony could also be viewed poorly in the eyes of the jury. 

"It wouldn't surprise me if there was at least one juror who found each of their reactions to be inappropriate or not credible or in some way negative," he said. 

He added: "As for Heard, you don't want to be staring straight ahead with a deadpan expression on your face. Both should be trying to appear sympathetic, humane and like the victim." 

Depp, who claims it was he who was the victim of abuse at the hands of his ex-wife, is seeking damages for a Washington Post opinion piece written by Heard in 2018, in which she identified herself as a victim of domestic and sexual violence. 

While she didn't name Depp – her husband of two years – he believes it ultimately defamed him and was the reason for him losing roles in his blockbuster movie franchises, including Pirates and Fantastic Beasts. 

Depp is seeking damages for a Washington Post opinion piece written by Heard in 2018, in which she identified herself as a victim of domestic and sexual violence. Photo / Getty Images 

Berlik added that both sides face losing because they were yet to meet the required threshold to prove their individual claims. 

"I don't think either side will get anything," he said. 

"Most of what I'm hearing so far is about all kinds of details about all sorts of incidents with fingers getting chopped off and people pooping in beds and doing cocaine … But when you read the op-ed, there's not a lot in there and I'd expect Heard's lawyer to instruct the jury very carefully about what this case is really about." 

The trial is currently on a break, with a cross-examination of Heard's claims to start when the court reconvenes on May 16.