The R&B star - who took to the stage to perform a medley of the King Of Pop's hits - broke down as he tried to sing Man In The Mirror.
Us Weekly alleged Chris, 21, used eye drops to induce the tears.
'He rubbed it in and he started crying,' a source told the magazine.
But now Chris's spokesperson has set the record straight.
'[The report is] completely untrue,' the rep tells Access Hollywood.
Michael, 50, died on 25 June 2009 after having a cardiac arrest at his LA home.
SEE PICTURES Rihanna and Chris Brown - their love story>>
SEE PICTURES Michael Jackson's This Is It premiere>>
SEE PICTURES The stars at Michael Jackson's memorial>>
SEE PICTURES Michael Jackson - life of a legend>>
SEE VIDEO Chris Brown cries during Michael Jackson tribute...
SEE VIDEO Stars pay tribute to Michael Jackson...
