The US government will drop an investigation into the Ford Explorer requested by tyre maker Firestone over a series of fatal accidents involving the vehicle.

The National Highway Traffic Safety Administration reviewed safety data, after Firestone claimed Ford's popular sports utility vehicle (SUV) was defective.

"The data does not support Firestone's contention that Explorers stand out from other SUVs with respect to its handling characteristics following a tread separation," said NHTSA Administrator Jeffrey Runge.

Explorer rollover accidents blamed on Firestone tyre tread separations have been linked to 271 deaths and 800 injuries.

Ford and Firestone have been reeling for more than a year because of the crisis and they blame each other for the tyre debacle.

Firestone launched two recalls totalling 10 million tyres mainly installed as standard equipment on an estimated 3 to 4 million Ford Explorers.

Both companies already are facing hundreds of personal-injury lawsuits in courts in the US and other countries.

The two companies have already suffered huge financial losses and the chief executives of both Firestone and Ford have been replaced.