The draft amendment states that the right not to be charged retroactively is a basic human right that cannot be breached under any circumstances. 'However there is a serious risk that this amendment will be used not to protect human rights but to shelter those responsible for violating them,' Amnesty International said.

While it allows for suspects to be tried under existing criminal law, there are fears that it will be used to protect senior military and government officials from being brought to justice for crimes not covered by Indonesia's domestic law, such as crimes against humanity and torture.

'The fact that Indonesia has not yet incorporated or does not explicity forbid crimes such as torture or crimes against humanity within its domestic criminal law does not excuse it from its international responsibility to pursue judicial investigations into these cases,' the organisation said.

While international law does not permit the retroactive application of criminal laws, the principle does not prevent the bringing to justice of any persons for acts that constitute crimes under international law such as crimes against humanity and torture.

This principle appeared to have been accepted in draft legislation for the establishment of Human Rights Tribunals which is currently awaiting ratification by the lower house of parliament. Under the proposed legislation the possibility exists for ad hoc tribunals to be established for past cases of gross human rights violations.

It was expected that an ad hoc tribunal would be established to try those suspected of responsibility for crimes committed in East Timor during 1999, investigations in to which are still ongoing. There are now concerns that the amendment might be used to try and block prosecutions under the proposed Tribunal.

The move to set up Human Rights Tribunals, combined with efforts to investigate a number of past cases, was a positive sign of a new willingness to confront the appalling human rights record of the Indonesian security forces. 'The proposed amendment could set the clock back years and casts doubt on the seriousness with which Indonesia is pursuing investigations including into crimes committed in East Timor last year,' said Amnesty International.

In Indonesia itself there are many thousands of unresolved cases of unlawful killings,'disappearances', torture - including rape, and other human rights violations. 'Only by addressing these past cases will Indonesia be able to begin to build a future based on justice and the rule of law', said Amnesty International.

'Any attempt to shield perpetrators of past human rights violations would effectively render all the recent efforts to end impunity in Indonesia meaningless.'

Although cases could still be pursued for crimes already contained in Indonesia's Criminal Code, the limited scope of the Code and narrow definition of some crimes means that many of those guilty of grave human rights violations could escape prosecution. 'Past experience has shown the Criminal Code to be inadequate for addressing the large-scale violations which have taken place in Indonesia - investigation and prosecutions are infrequent, only junior officers end up in court and sentences rarely reflect the seriousness of the crimes,' said Amnesty International.

'The principle of non-retroactivity must not be used as a backdoor for those responsible for the massive violations that have taken place over the years, including those who designed and directed policy,' said Amnesty International.