Robert Go, Jakarta – Indonesian Trade and Industry Minister Rini Suwandi will answer legislators' summons next Tuesday and face parliamentary grilling over her involvement in Sukhoigate, a scandal involving Jakarta's purchase of combat aircraft and helicopters from Russia in April.

A source close to the minister said she was currently in Shanghai on official business but would be back in Jakarta by the weekend.

The source said: "She should be available that day. She will also clarify there has been no wrongdoing, that she simply facilitated improving trade relations with Russia."

The central issue here is the government's decision to buy four Sukhoi jets and two helicopters from Moscow. Indonesia made a down payment of US$26 million and will complete the US$197 million purchase using a barter mechanism involving more than 30 commodities.

Nobody complained when the deal was first announced in April, but the issue has become a hot topic in recent weeks, with a number of MPs questioning its specifics.

At stake is more than just Ms Rini's job. MPs' findings may have implications for President Megawati Sukarnoputri's chances of re-election and her PDI-P party's reputation with voters.

The special parliamentary commission tasked with looking into the matter has so far questioned at least four businessmen linked to the Sukhoi negotiations.

Next Tuesday, legislators want to know why it was Ms Rini, instead of Defence Minister Matori Abdul Djalil, who negotiated the purchase with the Russians.

MP Joko Susilo, a member of the Sukhoigate commission, said: "She had no right to buy the jets. The laws are clear. Such purchases must go through the Defence Ministry."

Critics, including former minister Dr Rizal Ramli, questioned the wisdom of buying only four jets instead of the customary squadron-strength of 12. Another complaint is that purchasing Sukhois would require Indonesia to revamp its entire defensive radar system at a huge cost and complicate its spare parts and weaponry caches.

Without reprogramming, Indonesia's French-made radar gear will identify Russian-built jets as enemy craft. The air force's fleet consists mainly of fighter jets made by the Americans and the British.

Dr Rizal, a former Cabinet member, said: "The specifications ... were not properly thought out. The jets don't constitute an effective fighting force. "This is a result of the fact that these negotiations were led by Minister of Industry and Trade Rini Suwandi, who does not have the authority, knowledge and understanding of aircraft and military equipment to undertake this task."

MPs are also keen to probe Ms Rini on side-allegations connected to the Sukhoi deal, including a claim that she acted illegally to bring financial benefits to Ms Megawati's party in the run-up to the next election. Allegations are surfacing in Jakarta that PDI-P or businessmen closely associated with the party stand to make millions of dollars on side-deals connected to the Sukhoi purchase.

Ms Megawati's aides, in defence, say her political opponents are looking to make an issue out of legitimate deals and trying to tarnish her image. Indeed, those who have pushed for the Sukhoi investigations belong mostly to rival parties to PDI-P, they said, blaming political bickering for the entire scandal.

But the government's critics said they have a point, and a nobler mission here. Mr Joko said: "We need to make sure the process of barter for the jets will be conducted in a transparent way. A possible scenario is that businessmen from whom the state would have to buy the commodities it would trade to Moscow mark up their prices."