The former friends are currently facing off in court after Mr Hands claimed his company Terra Firma was duped into paying over the odds for the music company by Mr Wormsley.
According to Mr Hands, the Citigroup banker told him in May 2007 that Cerberus Capital Management was also planning a bid for EMI and advised Terra Firma to put in a higher offer, reports the Guardian.
Mr Wormsley denied the claims and said he had remained friends with Mr Hands until December 2009 when Terra Firma lodged its complaint against Citigroup.
"It was a unique experience to be accused by an important client," said the banker.
Terra Firma is seeking up to $8 billion in damages from Citigroup in the trial, after it paid Â£4.2 billion ($6.67 billion) in 2007 for the British music company, which has gone on to struggle financially since the acquisition.
By Asim Shah