Mitsubishi Motors has announced its president, Tetsuro Aikawa, will step down in the wake of the company's test-fixing scandal.

The Japanese carmaker has already admitted that it has been falsifying fuel efficiency tests for decades.

After Mitsubishi's share price slumped by more than 50%, fellow carmaker Nissan moved in to take a controlling stake in Mitsubishi.

In April, Mitsubishi Motors admitted it had rigged tests for the past 25 years.

Regulations changed in 1991 to better reflect stop-start urban driving, but Mitsubishi failed to heed the change.

Meanwhile, fellow Japanese carmaker Suzuki has said it has found "discrepancies" in its fuel and emissions testing, but denies cheating.