A fire on the sixth floor of the Income Tax department's headquarters here on Thursday night gutted several important tax-related files inside the storeroom, sources said. 

The I-T Commissioner and other officials rushed to the scene at around 11 pm, but did not disclose the files that were gutted in the fire. 

Fire tenders were used for more than 4 hours to douse the blaze. 

The private security guards manning the I-T building rang up Fire Brigade and other officials when the fire was first noticed. 

The cause of fire is yet to be ascertained.