Google has responded to accusations of "airbrushing history" in its use of controversial images of New Orleans which showed no signs of the devastation caused by Hurricane Katrina. 

The conflict stems from Google's decision to replace images or areas ravaged by Hurricane Katrina with photos taken before the 2005 storm.

The imagery angered New Orleans residents and prompted a letter (PDF) from the House Committee on Science and Technology.

Google Maps director John Hanke said in a written statement that the move was an effort to improve the quality of Google Maps, and not an attempt to erase the evidence of Hurricane Katrina.

"In September 2006, the storm imagery was replaced with pre-Katrina aerial photography of much higher resolution as part of a regular series of global data enhancements," said Hanke.

To rectify the situation, Google said that it had speeded up the processing of newer high-resolution images that correctly display storm damage.

The images now show the effects of the storm, which killed 1,826 people and caused more than $81bn in damage.

Hanke stopped short of issuing an apology, and pointed out that the pre-Katrina images had been in use for more than six months.

"Make no mistake, this was not any effort on our part to rewrite history," he said.