Joorabchian has accused the Hammers of making misleading statements about Tevez and threatened to bring "the true circumstances" of the 23-year-old's position to the attention of "a higher authority".
West Ham insist every document relating to Tevez has already been handed over to the Premier League and are happy to accept any decision made by FIFA.
The club said in a strongly-worded statement on the club's official website: "West Ham United totally rejects the latest outburst and threats issued in the name of Kia Joorabchian in relation to the situation regarding Carlos Tevez.
"Mr Joorabchian entered into agreements with the previous regime at West Ham at a time in which he was attempting to take over the club. Those arrangements, since terminated by West Ham, led the club into serious disciplinary difficulties for which the club has paid a heavy price.
"It is absolutely clear that the only contract relating to Carlos Tevez recognised by West Ham and the Premier League is the player's four-year contract which runs until June 2010. All other arrangements were terminated by West Ham on 27th April 2007 and no legal challenge to that termination has occurred.
"West Ham can also confirm that all documentation regarding the club and Carlos Tevez has already been submitted to the Premier League and fully scrutinised by them. We have ensured full disclosure."
West Ham insist they tried their best to persuade Tevez to stay by offering a better deal, and that if he wants to move to Manchester United then the Premier League champions have to make an acceptable offer.
The statement adds: "The club has in recent weeks made every effort to keep Carlos Tevez at West Ham and indeed offered significantly improved terms and conditions to the player, which were not accepted.
"However a transfer of a properly registered player cannot occur without agreement between two clubs and the Premier League.
"Without such an agreement we believe that it is in the interest of all parties to resolve this issue as quickly as possible through the procedures laid down by FIFA.
"Public threats and accusations are irrelevant, let FIFA decide and West Ham will accept that judgement whatever the outcome. The time has come to settle this matter in a way which will allow everyone concerned to move on."