Ashley has accused Jimenez of fraud and forgery and says he is owed £3m. Jimenez disputes the claims.
Former vice-president Tony Jimenez made the allegations during the latest stage of a High Court dispute between Ashley and Jimenez, in which the Magpies' owner is suing his former business partner.
Jimenez has been accused of fraud and forgery and says he is owed £3m.
Jimenez's lawyer, Adam Johnson QC, told 'Sky Sports': "Mr Ashley refused to meet a potential buyer who went on to purchase Manchester City Football Club.
"He (Jimenez) lined up some further potential buyers and Mr Ashley then visited Dubai between September 13 and 18 2008 in order to meet them.
"Mr Jimenez says that on the evening of September 16 2008, Mr Ashley created a disturbance in a bar in Dubai.
"Although Mr Jimenez helped Mr Ashley minimise the impact of the trouble, it again ruined the potential sale of Newcastle United Football Club that Mr Jimenez had lined up."
Ashley bought Newcastle in 2007 and has been deeply unpopular with Magpies fans for the majority of his tenure.