On April 6, 2001, Samberg in an email pressed Zilkha for any "tidbits" about Microsoft. Zilkha responded the next day that he would get back to Samberg "ASAP."

Three days later, Samberg, who had been betting that Microsoft's stock would go down, reversed course and began amassing 30,000 Microsoft options in a bet the stock would go up, according to S.E.C. records from the case.

On April 17, Zilkha reported in an email to Samberg that Microsoft's chief financial officer had been unusually upbeat in advance of the company's pending quarterly earnings announcement. The email appears in S.E.C. files.

Microsoft announced its earnings on April 19, beating analysts' expectations. The stock rose, and a day later Samberg closed out his positions, reaping that $12 million profit. That day, Samberg emailed Zilkha that "I shouldn't say this, but you probably have paid for yourself already," investigators found.

Samberg fired Zilkha months later in 2001, after Zilkha's contacts inside Microsoft evidently had stopped talking to him, according to records from the S.E.C. investigation.

After that, Zilkha had no known personal or financial dealings with Samberg or Pequot.

S.E.C. records made public in the case show that at one point in the investigation the S.E.C. enforcement division, which can only file civil lawsuits, had brought its evidence to the Federal Bureau of Investigation and federal prosecutors in an attempt to interest them in opening a criminal investigation.

No charges were ever filed, although F.B.I. agents did interview Zilkha, according to a 2006 S.E.C. memo written just before the investigation concluded. After talking to him alone, the F.B.I. joined with the S.E.C. and the U.S. Attorney's office to grant Zilkha limited immunity from prosecution and jointly questioned him under oath.

The S.E.C. memo and other records, though, show that investigators considered the information Zilkha gave them to be of little use. "Zilkha proffered that he had obtained information from Microsoft employees and provided it to Samberg, but did not believe the information was either material or confidential," the memo said.

Samberg, when he was questioned by the S.E.C. in 2006, testified that he couldn't remember why he had made the Microsoft trades, but denied that he had received any inside information on Microsoft.

Information about the recent payments by Samberg or Pequot to Zilkha surfaced in a long-running, fiercely contested divorce case between Zilkha and his former wife, Karen. Their marriage was dissolved in 2005, but Zilkha was required to continue filing regular financial statements with the court.

One of those statements show that in January 2008, Zilkha for the first time disclosed that he had received payments totaling $1.4 million, and expected to receive an additional $700,000 in 2009.

Karen Zilkha's lawyers moved to question both David Zilkha and Samberg under oath, to find out if an agreement to pay the money had been made before the divorce was made final.