Rocker Melissa Etheridge has denied she and Tammy Lynn Michaels were ever married, celebrity website TMZ.com reported.

Last April, the two women announced they were splitting up after nine years. In separate filings to end their California domestic partnership, each claim “irreconcilable differences.” Etheridge is asking the court for joint custody of the couple's twin 4-year-old children, son Miller and daughter Johnnie Rose. Michaels, who gave birth to the twins, says she wants full custody of the children with visitation rights for Etheridge.

Michaels has previously claimed that Etheridge left her and their children penniless, allegations Etheridge has denied.

The women continue to argue about child custody, child support, spousal support and division of property.

Michaels, 36, said on her blog that she gave up an acting career in 2001 to care for the children. She has filed for a dissolution of marriage, rather than domestic partnership, believing she is more likely to prevail in her claim for spousal supports if the court views their relationship as a marriage.

According to TMZ.com, Etheridge, 50, has said that their vows were “nothing more than a non-binding commitment ceremony.”