Mitsubishi Motors admits cheating fuel tests since 1991

Mitsubishi Motors has admitted to falsifying some fuel consumption tests since 1991.

The admission follows last week's revelation that it had falsified fuel economy data for more than 600,000 vehicles sold in Japan.

"For the domestic market, we have been using that method since 1991," said vice-president Ryugo Nakao at a press conference in Tokyo on Tuesday, BBC News reprots.

The number of models affected was not yet known, he added.

Tetsuro Aikawa, Mitsubishi Motors' president, said an inquiry was continuing, suggesting that more irregularities could be found.

"We don't know the whole picture and we are in the process of trying to determine that. I feel a great responsibility," he said.

Shares fell a further 10% in Tokyo on Tuesday, bringing the slide since the scandal erupted to almost 50%.