The federal government sued the estate of Enron Corp.’s deceased founder Kenneth Lay, seeking to strip it of $12.7 million in ill-gotten gains from an accounting fraud that investors claim cost them $30 billion.

Prosecutors linked the suit, filed yesterday in federal court in Houston, to the October 17 voiding of Lay’s conviction on 10 counts of conspiracy, securities fraud and bank fraud. A federal judge tossed out the May verdict on grounds that Lay hadn’t had a chance to appeal it before he died of heart disease in July. The ruling blocked the government’s effort to seize the estate’s assets in the criminal case.

The suit is “a civil forfeiture action to recover property that constitutes proceeds of the fraud proven in the criminal case against Lay,”the Assistant U.S. Attorney General, Alice Fisher, said in a statement yesterday.

The government seeks to seize Lay’s River Oaks condominium in Houston, property associated with a family investment partnership and a Bank of America account with more than $22,000 — “all proceeds obtained directly or indirectly as a result of various federal crimes,” Mrs. Fisher said.

Prosecutors claim that $2.5 million of the current market value of Lay’s condo and $10 million in the family partnership’s property are traceable to Lay’s illegal activity, which the government will have to prove at trial.

Michael Ramsey, Lay’s lead trial lawyer, could not immediately be reached for comment. Samuel Buffone, Lay’s appellate lawyer, declined to comment on the government’s suit.