Indonesian authorities have launched a criminal investigation into a group of historians and education ministry officials over new school texts offering an alternative version of events surrounding the failed 1965 coup that led to the rise of former President Suharto.

Schoolchildren were taught throughout Mr Suharto’s 32-year rule that the then-general led a successful campaign to eliminate the Indonesian Communist party, or PKI, after a failed communist coup on September 30 1965.

That version has been challenged since Mr Suharto’s May 1998 fall, with education officials in 2004 introducing a new curriculum allowing discussion of alternative scenarios even as an official panel of historians set about trying to establish exactly what happened.

Also discussed more readily since Mr Suharto’s ousting has been the killing of between 500,000 and 2m suspected communists by the military and Muslim militias.

But Bambang Sudibyo, Indonesia’s education minister, said on Monday that the government of President Susilo Bambang Yudhoyono, a former Suharto-era general, had now decided to abandon the 2004 curriculum. Mr Sudibyo said he had also asked the country’s attorney-general to investigate the historians and other officials responsible for textbooks derived from the 2004 curriculum that failed to blame the PKI for the coup.

A spokesman for the attorney-general’s office confirmed an investigation was under way into the publication of the history books, saying they had caused “restlessness amongst the people”.

The decision is likely to raise memories of Mr Suharto’s authoritarian rule. It will also prompt questions about the nature of Mr Yudhoyono’s government and the many Suharto loyalists present in his cabinet.

The 2004 curriculum stopped short of attributing blame to any one group for the events of 1965 and historians say it is unlikely Indonesians will ever know for sure what happened.

Taufik Abdullah, the prominent historian leading a government-appointed team formed to compile a definitive version of events, said his group hoped to publish a complete history of the attempted coup later this year.

But he said it had been impossible to determine exactly who was responsible. “For every source we find two or three counter-sources,” he said.

Juwono Sudarsono, the former education minister who advocated the initial revision of the history curriculum after Mr Suharto’s fall, said he was concerned the 2004 curriculum went too far in removing any blame from the PKI.

But Mr Sudarsono, the defence minister in Mr Yudhoyono’s cabinet, also said the launching of a formal investigation “is a bit worrying”.

Mr Suharto and his family have been accused of amassing a fortune of up to $35bn (€27.6bn, £18.6bn) during his rule, prompting Transparency International in 2004 to dub him the most successful kleptocrat of the 20th century.

Mr Yudhoyono’s government dropped efforts to prosecute Mr Suharto for corruption after he was taken ill in May.