Gordon Ramsay's father-in-law hacked into the celebrity chef's emails almost 2000 times to try to dig up dirt on him, a London court was told on Friday.
Chris Hutcheson, 68, allegedly rifled through password-protected accounts after being thrown out of the family's lucrative business empire amid a bitter row between the pair.
The wealthy businessman searched emails and company computer systems to try to find mud to throw at his son-in-law following his sacking, it is claimed.
Another alleged motive is that Hutcheson suspected Ramsay, 50, had leaked a photo of his mistress Sara Stewart and was searching for evidence, the court heard.
Hutcheson appeared in the dock at Westminster Magistrates' Court with his son Adam, 46, and daughter Orlanda Butland, 45.
The trio, along with Hutcheson's 37-year-old son by another relationship, who is also called Chris, are charged with conspiring to access Ramsay's data.
The hacking spree is alleged to have taken place between October 2010 and March 2011 after Hutcheson snr was sacked from Gordon Ramsay Holdings Ltd.
Prosecutor Dan Suter said police found emails in which the four discussed "cracking the passwords". He said: "It's a conspiracy to unlawfully access a computer system. It's a convoluted, voluminous case."
Mr Suter added that experts examined records on Ramsay's computer system, which gave clues as to who was responsible.
"A Met Police expert reviewed those log files, and found almost 2000 unauthorised entries into the accounts of Gordon Ramsay Holdings Ltd," he said.
Hutcheson, who lives in Druillat, France, was charged after a lengthy investigation by detectives from Scotland Yard's Operation Tuleta, one of the three main inquiries that stemmed from the phone hacking scandal. Up to 18 people were arrested as officers probed claims illicit software and other techniques were used to access information held on computers. Ramsay once boasted he and his father-in-law were inseparable, and appointed him chief executive of his empire.
But the pair became locked in a toxic feud in 2010 when they fell out over claims Hutcheson borrowed 1.5 million ($2.65m), after which he left his role.
In an ugly 2012 High Court battle, Hutcheson branded his son-in-law a fame-obsessed 'monster' and accused him of turning his daughter Tana, 42, against him.
In response, Ramsay called him a 'dictator', accusing him of womanising and leading a 'very complex life'. His claims were sparked by a 2011 revelation that Hutcheson had fathered two children, including Chris jnr, with another mistress, Frances Collins.
District Judge Emma Arbuthnot ordered the four to appear at the Old Bailey next month. They were released on bail.