Racing Point co-owner Lawrence Stroll has said he is "appalled" by the unsporting behaviour of his Formula One rivals – accusing Ferrari, McLaren, Renault and Williams of dragging his team's name "through the mud".
The four teams have all lodged their intention to appeal Racing Point's FIA punishment for copying parts of the Mercedes that Lewis Hamilton drove to a sixth world championship last year.
Racing Point, who were docked 15 points and fined £361,000 by the FIA, are much improved this season, with stand-in driver Nico Hulkenberg starting third for Sunday's race at Silverstone, behind pole-sitter Valtteri Bottas and Hamilton in the sister Mercedes.
Racing Point's rivals are keen to understand if there could be other parts on the car which are identical to last year's Mercedes.
But Canadian fashion billionaire Stroll, who took over the Silverstone-based team two years ago, issued a strongly-worded statement denying his rivals' accusations. Racing Point are also appealing the FIA's verdict.
"I do not often speak publicly, however I am extremely angry at any suggestion we have been underhand or have cheated – particularly those comments coming from our competitors," said Stroll.
"I have never cheated at anything in my life. These accusations are completely unacceptable and not true. My integrity – and that of my team – are beyond question.
"Beyond the clear fact that Racing Point complied with the technical regulations, I am appalled by the way Renault, McLaren, Ferrari and Williams have taken this opportunity to appeal, and in doing so attempted to detract from our performances.
"They are dragging our name through the mud and I will not stand by nor accept this. I am truly upset to see the poor sportsmanship of our competitors."
Hamilton's Mercedes team have been pulled into the scandal after it was revealed they had supplied a complete set of last year's brake ducts to Racing Point on January 6.
It was also established during the FIA's investigation that they provided Racing Point with computer-aided design models for the parts which assisted them in building this year's car, dubbed the "Pink Mercedes".
Team principal Toto Wolff defended his team's position earlier this week, but he was pulled from a media appearance on Saturday night, with Mercedes citing a "scheduling clash".
F1's governing body ruled that the transfer of brake ducts from Mercedes to Racing Point did not constitute a "significant breach of the sporting regulations", and the transferring of data was within the rules.
However, Racing Point were found guilty of copying Mercedes' parts. They will be allowed to continue to use them this season.
"I intend to take all necessary actions to prove our innocence," added the 61-year-old Stroll, whose son Lance, drives for Racing Point.
"My team has worked tirelessly to deliver the competitive car we have on the grid."
Ferrari, McLaren, Renault and Williams have until Wednesday to decide if they want to press ahead with their action, which would involve lawyers at the FIA's Court of Appeal.