Cecilia Duncan - who was hired to look after the `Yeah!` hitmaker`s two sons, Usher V, five, and four-year-old Naviyd between December 2010 and September 2012 - has filed a lawsuit against the singer, alleging she was "overworked" and was not paid overtime, according to TMZ.
The ex-nanny claims she often worked over 40 hours a week, but wasn`t being compensated for the extra hours and when she brought up her grievance to the 34-year-old star in 2011, he ignored her claims for more than a year and subsequently fired her last year.
Cecilia is thought to have filed a six-figure lawsuit against the `Scream` singer for wrongful termination, failure to pay wages and is also seeking other unspecified damages.
However, Usher`s camp denies any wrongdoing, branding the nanny`s claims "completely false" and the lawsuit "frivolous".
The `Climax` crooner was locked in a bitter custody battle with ex-wife Tameka Foster - the mother of his children - last year, with the judge eventually siding with the singer and awarding him primary custody of the couple`s two sons.
Tameka attempted to request a retrial - citing that the judge in the case was biased after receiving campaign contributions from Usher`s manager - but the appeal was denied.