Gordon Ramsay has denied lying in court and "manufacturing" displeasure about his father-in-law using a ghost writer machine to "forge" his signature.
The celebrity chef is claiming the machine was used without his knowledge to make him personally liable for the £640,000-a-year annual rental on the historic York & Albany pub near Regent's Park in London.
He is asking a High Court judge to grant him a declaration that the rental guarantee is not binding because his signature "was not lawfully authorised" when the 25-year lease was signed in 2007.
The chef says his wife Tana's father, Christopher Hutcheson, acted as business manager for the Ramsay group of companies until dismissed in 2010 and used the machine to forge his signature on the agreement.
Ramsay told Chancery Division judge Mr Justice Morgan his "deep and extensive trust in Hutcheson was entirely misplaced" and his father-in-law defrauded him and the group "of hundreds of thousands of pounds".
Film director Gary Love, who owns the York & Albany, has described Ramsay's allegation as an "absurd" attempt to wriggle out of his rental commitments.
Romie Tager QC cross-examined Ramsay on Mr Love's behalf. He suggested the chef was not telling the truth and knew about Mr Hutcheson using the ghost writer, which electronically replicates a signature using a fountain pen or ballpoint, to sign business documents long before the York & Albany deal.
Ramsay told the judge he did not know and was telling the truth.
Mr Tager suggested to him: "When you expressed great displeasure about the signature being forged on documents, that is all manufactured.
"The fact is you didn't care whether the machine was used to write the signature and you don't really care today."
Ramsay said: "That is untrue. I brought this case to court because of the shock and unhappiness of being somewhat stitched on a guarantee my wife and I not were not a party to."
Gordon Ramsay Holdings (GRH) won a bidding war to secure the 160-year-old York & Albany building in the exclusive area of Regent's Park, north London.
The Independent reported that this pushed the rent far higher than the market rate and Ramsay has since turned the pub into an upmarket restaurant, bar and hotel.
The chef said in a written statement that the lease - though not binding on him personally - was binding on Gordon Ramsay Holdings Ltd (GRHL) and on Gordon Ramsay Holdings International Ltd (GRHI).
Ramsay said it would have been "unthinkable" to enter into a personal guarantee for each of the many restaurants he opened.
He said that would entirely defeat the purpose of running each of them through separate corporate vehicles.
The York & Albany was "not a business venture I was personally taking forward - I was merely lending my name to help promote it and attract customers".
He said: "I am appalled at the extent to which Chris used the Ghost Writer machine to sign documents ostensibly on my behalf in circumstances where I had no knowledge of the documents that were being 'signed' or the matters to which they referred."