NEW YORK (REUTERS) - Two US senators on Wednesday raised the possibility of a sixth fatality linked to Takata Corp air bags, as they announced a news conference to introduce the sister of someone who died in an Arizona accident in 2003.

So far, five fatalities in Virginia, Oklahoma, Florida, California and Malaysia have been linked to faulty Takata air bag inflators.

Democratic Senators Edward Markey and Richard Blumenthal said in a statement that the sister of the Arizona victim will be at the news conference on Thursday in Washington.

The press conference will take place ahead of a Senate hearing at which officials from Takata, Honda Motor, Chrysler Group and the National Highway Traffic Safety Administration (NHTSA) are scheduled to testify regarding recalls involving the Takata air bags.

All of the deaths linked to the faulty Takata air bags, which can potentially explode and spray metal shrapnel at occupants of the vehicle, occurred in Honda cars.

A Honda spokesman said the Japanese automaker was "not aware of an incident in 2003" involving an air bag-related fatality in one of its vehicles. Takata US spokesman Alby Berman also said the company was not aware of this incident mentioned by the senators and was looking into it.

On Tuesday, NHTSA said it had told Takata and five automakers - Ford, Mazda, Honda, Chrysler and BMW - to expand nationwide a regional US recall of vehicles with the potentially defective air bags.

The regional recall has involved 4.1 million cars in hot and humid areas, where the air bags may be prone to fail, including Florida, Alabama, Mississippi, Georgia, Louisiana and parts of Texas along the Gulf of Mexico.

Around 16 million cars with Takata air bags have been recalled worldwide over the past six years, with more than 10 million of those in the United States.