A former Megaupload employee caught up in the world's biggest copyright case has reportedly died. 

Finn Batato, 48, whose long battle with terminal cancer saw an FBI-inspired extradition push against him dropped last year, passed away overnight, according to Megaupload founder and long-time close friend Kim Dotcom. 

Dotcom paid tribute to his best friend and former Megaupload marketing director in an emotional on online platform Substack this morning. 

"Finn was my best friend and a great family man," Dotcom wrote. 

"His top priority in life was the happiness of the people he cared about." 

Batato leaves behind wife Simone Meier and, between them, four children including a young son born in October. 

In his last interview earlier this year, Batato told the Herald from his native Germany of his frustration at being caught up in what he called an unfair prosecution. 

"My name is at play here. I'm very attached to my family name," he said. 

"It really irks me that we're in this and someone is trying to make like we are criminals. I don't like that. I didn't break the law." 

Batato came to New Zealand in January 2012 for the birthday of his long-time friend Dotcom. 

It was intended to be a quick visit but coincided with the raid of Dotcom's rented Coatesville mansion which saw the pair arrested, along with Megaupload coders Mathias Ortmann and Bram van der Kolk. 

The quiet dropping of the extradition of Batato was signalled in a single line of a Court of Appeal judgment. 

"Until very recently, it [the United States] was also seeking the extradition of Mr Batato but due to health issues no longer does so." 

Bram Van der Kolk, Kim Dotcom, Mathias Ortmann and Finn Batato outside the Auckland High Court in 2012, the year of the Megaupload raid. Photo / File 

A deal was cut between Ortmann, van der Kolk and the US last month that will reportedly see the pair facing equivalent charges in New Zealand courts and the extradition dropped once those have been heard. 

It means Dotcom is the only one of the original accused left facing extradition from New Zealand. 

In his tribute today, Dotcom talks about meeting Batato at the Skyline bar in Munich when Dotcom was just 18 years old – sparking a lifelong friendship. 

"A big part of our lives was the desire to accumulate great experiences at a young age with adventurous travel, delicious food and high speed driving to loud music," he wrote. 

"The countless hours that Finn and I spent laughing and enjoying life together will always be one of the highlights of my life. But Finn was also there when things were not so great." 

- by Kurt Bayer, NZ Herald