Actor Mel Gibson's ex girlfriend Oksana Grigorieva has filed for bankruptcy.

`The Lethal Weapon` star and the Russian songwriter were involved in a heated custody battle over their daughter Lucia in 2011, and Grigorieva won $750,000 (484,000 pounds) from the settlement, which is to be paid in instalments until 2016.

But three years later, her funds have dissipated, and Grigorieva has filed for bankruptcy, reports tmz.com.

In legal documents obtained by the news site, she has declared $48,000 (28,749 pounds) in assets, but $438,000 (262,590 pounds) in debts.

Grigorieva claims she is owed money for song royalties as well as paintings she's created.

And while her incoming funds include Gibson's $20,000 (11,990 pounds) a month in child support, as well as $2,500 (1,500 pounds) from actor Timothy Dalton, with whom she has a son, it is not enough to cover her debt.

In the bankruptcy documents, Grigorieva states that most of her debt stems from the legal fees she ran up during her custody battle against Gibson. She was initially offered a $15 million (9 million pounds) settlement from Gibson in 2010, but she refused it.