An 'emotionally battered' Amber Heard hired a notorious private investigator to dig up any dirt possible on her ex-husband Johnny Depp amid their ongoing bitter legal battle, but the investigator exclusively told DailyMail.com he found nothing.

Former porn star-turned Hollywood 'fixer' Paul Barresi says he was hired by Heard's legal team last summer to find people who had been verbally or physically abused by Depp and be star witnesses in the upcoming defamation cases in the UK and US.

Barresi, who has worked for the likes of Sylvester Stallone, Arnold Schwarzenegger and Eddie Murphy, explained he was hired to look into Depp's 'follies and vices' dating as far back as the actor's Viper Room days, which he co-owned in the 1990s.

But Barresi said he couldn't find anyone who had a bad word to say against Depp, 56, even after interviewing over 100 people across the US and Europe who had worked with Depp on films dating back 30 years.

An 'emotionally battered' Amber Heard hired a notorious private investigator to dig up any dirt possible on her ex-husband Johnny Depp amid their ongoing bitter legal battle, but the investigator exclusively told DailyMail.com he found nothing

'Amber's lawyers contacted me and said you're the right man for this job, that's how they brought me in. She was emotionally spent and battered and tormented - it was a volatile relationship,' Barresi told DailyMail.com.

But he admitted: 'I went to the US, France, Italy, Britain, everywhere that Johnny Depp roamed, everywhere he walked, I couldn't find one instance, or at least an admitted one, where he was physically abusive to a woman, smacked or beaten around, he's like an angel. Not one who said a deprecating thing.

'I interviewed dozens of people, who knew him going as far back as three decades ago, and nobody had one bad thing to say about him. In fact, they couldn't say enough about his ever flowing outpouring of generosity and tender heart.'

A spokesperson for Heard said: 'Mr Barresi hasn't been involved with Ms Heard's team since he was let go last year, and his account is entirely inconsistent with the testimony of multiple witnesses.'

Barresi (pictured) said he couldn't find anyone who had a bad word to say against Depp even after interviewing over 100 people across the US and Europe who'd worked with Depp on films dating back 30 years

In an email, Barresi gave DailyMail.com examples of the plaudits to Depp, writing: 'Jane Galli, head of the make up department on City Of Lies had nothing but praise for Depp. She had worked with him in the past on Public Enemy and Pirates. 'She said: ''He's a real sweetie.''

'City of Lies director Brad Furman told me Johnny was a true professional and wonderful human being in every sense of the word and assistant director Paul Silver told me although Johnny was not always on time, held up the shoot sometimes, he was a professional and always delivered.

'I asked Silver whether Depp ever lost his cool, Silver said: ''All artists have a temper''.'

Yet Barresi claimed this doesn't tell the full story of Depp's 'bizarre' character and the 'disgusting' entourage he hangs around with.

The investigator said he interviewed Depp's close friend of 30 years, celebrity tattooist Jonathan Shaw, who did most of his body artwork.

Barresi said Shaw, 66, told him: 'The only thing I would be willing to help that gold digging w***e do is help load the gun she wanted to use to blow her f**king brains out.'

The PI - who was once hired to investigate unproven claims that Tom Cruise had a gay affair - went onto claim that Heard grew frustrated with being verbally abused by his associates.

Barresi, 71, said: 'I have to say that the people around Depp are more volatile, even his lawyer Adam Waldman, who is like a bulldog, and called me a ''bag man''.'

The investigator said he interviewed Depp's close friend of 30 years, celebrity tattooist Jonathan Shaw (pictured together), who did most of his body artwork. Barresi said Shaw, 66, told him: 'The only thing I would be willing to help that gold digging w***e do is help load the gun she wanted to use to blow her f**king brains out'

At the time of Heard and Depp's split in May 2016, Shaw wrote on Facebook: 'As a close personal friend of Johnny Depp's for over 30 years, I've only seen him to be one of the kindest, gentlest, most sensitive and generous human beings I've ever had the great pleasure to know. The man is constitutionally incapable of raising a violent hand to a woman'

Depp has taken on a London tabloid over a 2018 article that described him as 'wife beater' and allegedly damaged his standing as a globally famed movie star, with Heard scheduled to give testimony

Barresi continued: 'That was why Amber's frustrations grew. I don't think there's much difference between verbal and physical abuse, it does equal harm.

'I wanted to stress the point that over the years based on people I spoke with close to Depp, he is without question proven himself a man who is generous to a fault. Dating as far back as the mid-nineties, he's covered legal costs, medical bills and even paid rent for his friends.

'The irony is they appear to have undying loyalty to him, but I'm not entirely convinced they are his friends.'

At the time of Heard and Depp's split in May 2016, the actor's friend Shaw wrote: 'As a close personal friend of Johnny Depp's for over 30 years, I've only seen him to be one of the kindest, gentlest, most sensitive and generous human beings I've ever had the great pleasure to know. The man is constitutionally incapable of raising a violent hand to a woman.

'Everything I know about Amber Heard, however (and it's a lot), seems to support the many claims that she is a lying, two-faced, bottom-feeding fame harpy, who lives by the old Hollywood code of ''hurray for me and f**k you!''

'It's disgustingly obvious to anyone with half a brain that the absurd contrived allegations about Johnny's behavior are nothing but a pathetic and desperate attempt to extort money from my dear little brother. Period.'

As part of Depp's $50m defamation case against Heard, he included images of his own bruised and battered face (pictured ) following Heard's alleged attacks

DailyMail.com previously published audio of Heard admitting to 'hitting' the Oscar nominee, and pelting him with pots, pans and vases. The fighting pair seem to refer to a violent incident that took place in Australia one month into their marriage in which Depp suffered a severed finger (pictured)

Heard cataloged the 'horrific' abuse she claims to have suffered at Depp's hands, describing him as 'the monster' and recalling many of the allegations she made during their divorce. The filing included photos of bruises and scars (left and right)

Amber Heard is pictured during her 2016 deposition where she described punching Depp in the face in attempt to stop him from hurting her sister, she said

Depp has taeken on a London tabloid over a 2018 article that described him as 'wife beater' and allegedly damaged his standing as a globally famed movie star, with Heard scheduled to give testimony.

And, later this year, hostilities will switch to Virginia where Depp has filed a $50 million suit over a Washington Post op-ed in which Heard lamented her experiences as a domestic violence victim.

Although the article didn't mention Depp by name, it allegedly led to him lose his prized role of Captain Jack Sparrow.

Barresi did find one unresolved issue regarding the disappearance of Depp's ex-business partner Anthony Fox.

Together they owned the Viper Room at the time River Phoenix died of a drug overdose in October 1993, but the relationship turned sour later on when Fox accused Depp and his associates of defrauding him out of club profits.

Shortly before Fox was due to testify, he disappeared on December 19, 2001 in Ventura County and hasn't been seen since. The investigation still open.

The lawsuit continued in Fox's absence and in 2004, Depp quietly settled, turning over his share of the nightclub to Fox's daughter, Amanda.

Barresi said Heard's legal team wasn't interested in this, but Heard was, with Barresi adding: 'Someone spoke to Amber and she said: ''No, let Paul go as far back as he can.''

Barresi showed DailyMail.com an email conversation with Ventura Criminal Investigative Technician Patrick Furlong, which revealed Furlong was inquiring about any information Barresi had on the missing Fox.

'It is unclear whether the Viper Room or the pending litigation had anything to do with his disappearance, however, Detective Furlong, whom I am working with on Fox's disappearance confirmed the case remains open and Fox still remains on the Endangered Missing Person's list,' Barresi said.