The Supreme Court has ruled that workers who cooperate with internal investigations of retaliation by their employers are sheltered by federal laws prohibiting job discrimination.

In an opinion Monday, the justices held that a longtime school system employee in Tennessee can pursue a civil rights lawsuit over her firing.

The court voted unanimously to reverse the 6th U.S. Circuit Court of Appeals' ruling that the anti-retaliation provision of Title VII of the 1964 Civil Rights Act does not apply to employees who merely cooperate with an internal probe rather than complain on their own or take part in a formal investigation.

Vicky Crawford was fired in 2003 after more than 30 years as an employee of the school system for Nashville, Tenn., and Davidson County.

She did not file a complaint about harassment by a school official. But she said she had been subject to unwanted sexual advances when she was interviewed by investigators for the school system who were looking into other employees' allegations against the director of employee relations.

Crawford was fired months later. The official was not disciplined.

She filed a federal lawsuit, but it was dismissed by a federal judge and upheld on appeal.