The Attorney-General, Andi Muhammad Ghalib, said the move - one step before a formal charge - could be taken based on evidence given by officials suspected of corruption.

"We will collect and recheck information given by former ministers, former director generals, or former officials," Mr Ghalib said. "Then we will see whether there is a strong ground to name Suharto as a suspect and take further measures - the information given by those who have been interrogated seems to lead us into that direction."

Controversial car project

Tommy: Barred from leaving the country

The case focuses on the Timor national car project run by Mr Suharto's youngest son, Hutomo "Tommy" Mandala Putra, which was given huge tax breaks and funds from a consortium headed by state banks. Mr Ghalib says the funding caused financial losses to the state.

Mr Suharto's son, who is also under investigation, has been banned from leaving the country. Both deny any wrongdoing.

Other Suharto children clinched lucrative government projects during his presidency including the construction of toll roads and the purchase of aircraft for the state-owned airline. Some estimates have put their total wealth as high as $40bn.

Pressure for trial

Questions have also been raised about various charity foundations chaired by Mr Suharto, as well as bank accounts and properties under his name.

The government is under intense public pressure to bring him to justice but that could also open the door to charges against ministers in the current government, many of whom held office during the Suharto era.

Mr Suharto has himself threatened to implicate others if he is put on trial.

Two weeks ago he was questioned for around four hours as part of a second investigation ordered by his successor, BJ Habibie, after a first inquiry had exonerated him.