Usher could leave his ex-wife homeless.

Tameka Foster is locked in a complicated legal battle with the 'OMG' singer, and is worried he could sell the Georgia mansion where she is living.

A clause in the couple's divorce settlement allows Usher to sell the property in the US at any time as long as he gives her 60 days notice, and sources tell she fears he will soon do just that, leaving her with mounting legal bills and nowhere to live.

Tameka has reportedly asked that she get a permanent home for her and their children, Usher, four, and Naviyd, three, but he has reportedly refused as he believes he has already paid her enough.

At the beginning of this month, the couple were ordered to work out their differences and come to an agreement over custody of their children, a sticking point in their divorce proceedings.

Usher, 33, and Tameka, 40, filed for divorce in June 2009 after almost two years of marriage. She later filed court documents in Georgia asking the singer to be stripped of joint physical custody of their sons.

Tameka has previously alleged Usher is behind on $34,000 worth of payments after promising her $5,000-a-month to pay for a nanny.