American politicians have begun looking into the collapse of Enron Corp, the largest ever bankruptcy in US history.

The United States House Energy and Commerce committee will request financial documents from Enron Corp and its auditor, Andersen, as a first in its lengthy investigation to find out how the energy giant descended into bankruptcy.

House committee aides said they met with Andersen representatives this week and would send three investigators to Enron's Houston headquarters.

Depending on the findings of the probe and hearings next month, the committee might support changes in accounting and trading laws if they helped Enron conceal the extent of its troubles, one committee spokesman said.

Enron Australia has an electricity derivatives book that has a net positive value of more than $5 million, according to its voluntary administrator. Co-administrator Mr Tony Sims said a valuation of the book at present market rates had found that about $20.5 million in contracts were in the black and $15.5 million were in the red.

Three of Enron Australia's trading companies went into voluntary administration on Monday after Enron Corp filed for Chapter 11 bankruptcy protection in the US.

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