Red chief executive Jim Jannard today launched a stinging attack on Arri, labelling the rival camera manufacturer “a fraud” amid allegations of corporate espionage.

It follows a December law suit filed by Red which alleged that Arri gained an unfair business advantage after one of its employees accessed the email account of the chief executive of digital cinema company Band Pro.

Red was involved in joint venture discussions with Band Pro at the time of the alleged hacking.

In a post on the Red User forum today Jannard said: “I used to love Arri. I have many Arri cameras. Arri was the epitome of everything cameras should be.

“Now I have noting (sic) but disdain for Arri. Email hacking. Telling the world that 1080P is good enough when they were secretly working on a 4K camera.”

In documents filed with the District Court of California on 21 December, Red alleged that former Arri vice president of market development for digital cameras Michael Bravin, who worked for Band Pro from 1993 to 2009, accessed Band Pro chief executive Amnon Band’s email account and read emails from Red CEO and owner Jannard to “gain confidential information related to the Red Epic camera to use for the advantage of Arri in the release of their Alexa camera”.

It also alleged that Arri “knowingly used competitive information about Red gathered by Bravin from the email account of Amnon Band for its own advantages.”

In September, Bravin pleaded guilty to unlawfully accessing the email server of Band Pro.

Red now wants a “preliminary and permanent injunction barring Arri from its continued benefit obtained from the unlawful intrusion into the private emails and reliance on the proprietary and confidential information of Red.”

Jannard continued: “I started Red because companies like Arri apparently do not have the industry’s best interests in mind. Arri used to be the ultimate. In my eyes Arri is now a fraud.”

Arri declined comment.