Singer Paulina Rubio's ex-husband is accusing her of concealing financial information pertaining to their divorce settlement and spousal support agreement.

The couple parted ways in March (13) after five years of marriage and The X Factor judge agreed to pay Nicolas Vallejo-Najera $6,750 (Gbp4,500) a month in spousal support for three years.

However, Vallejo-Najera claims the amount is based on a low estimate of the singer's income and he is accusing her of cheating him out of his rightful share of her fortune, according to

Rubio's lawyer is refuting the claims and tells the website his client was transparent in the the divorce proceeding and her ex is nothing but a "whiner".

The couple are still embroiled in a bitter custody battle over their three-year-old son.

Rubio signed on to host the third season of The X Factor in America earlier this year (13).