A Paris court has thrown out a legal case against nine activists who bared their breasts in a rowdy protest inside Notre Dame Cathedral, ruling that there was insufficient evidence of any material damage.

Prosecutors had sought thousands of dollars in fines against the activists from feminist group Femen who pounded a huge church bell in the landmark Paris cathedral in February last year to express anger at the Roman Catholic Church's opposition to gay marriage. They also staged a mock celebration of the resignation of Pope Benedict XVI.

The activists went on trial in July in a case pitting arguments for freedom of speech against proponents of freedom of religion.

The prosecutor requested fines of 1,500 euros ($2,040) against each activist for charges of damaging property.