Ford believes its Crown Victoria Police Interceptor, used by 85% of all US police officers, is safe, despite continuing allegations to the contrary, Dow Jones Newswires said.

The news agency said that the Detroit Free Press newspaper, investigating high-speed crashes involving the 'Crown Vic', reported on Tuesday that some police departments have added their own safety features after Ford delayed making modifications to the vehicle, following a number of fatal crashes.

Dow Jones said that Ford has acknowledged that at least 18 police officers have died since 1992 when their Crown Victoria cars caught fire after being hit from behind at very high speeds and, since October 2002, has offered a Police Package Upgrade Kit to safeguard against fuel tank punctures for the 350,000 vehicles on the road, while adding petrol tank shields to new police models it builds.

Ford spokeswoman Kristen Kinley told Dow Jones that police vehicles face special problems.

"It would be unreasonable to think that any design or technology could withstand crashes at speeds of 85 to 90 miles per hour," Kinley reportedly said.

Dow Jones noted that the Crown Victoria meets current government safety standards, with crash testing at 50 miles per hour (80km/h) but said that Tuesday's Free Press story noted that some crashes at lower speeds resulted in petrol tank punctures, although not all incidents were fatal.

Ford has no plans to make modifications to the Crown Victoria police vehicle, Kinley told Dow Jones.

"We have had dozens of meetings across the country," Kinley reportedly said, adding: "We addressed their concerns."

Dow Jones said that Ford faces a number of lawsuits around the country related to fatal police vehicle crashes.