There was not enough evidence to charge Mark Madoff with any financial crime after two years of investigation, officials familiar with the case said.
Word that Mark Madoff may not have faced federal charges in connection with ongoing tax fraud and Ponzi scheme investigations come after he killed himself Saturday in his Soho apartment.
Madoff's infamous father, convicted swindler Bernard Madoff, said through his lawyer Monday he would not request to attend his son's funeral out of "respect" for the family. Mark's body remains in a New York City morgue and no funeral arrangements have been announced.
Sources tell NBCNew York.com that the tax fraud investigation into Mark Madoff was active and ongoing - but at this time officials said there simply was not enough evidence to charge him criminally.
Madoff and his brother Andrew had long denied any involvement in their father's Ponzi scheme. Mark Madoff's lawyer had called his suicide "unnecessary."
"If he wasn't involved it certainly is a horrific tragedy," said former federal prosecutor Annemarie McAvoy. "It could be because of the shame that was involved in large part because he said people did not understand."
Before hanging himself with a dog leash as his two-year-old son slept nearby, Madoff sent emails to his wife and lawyer that read in part "No one wants to hear the truth."
But Madoff, who worked at his father's firm for years, never spoke publicly about suspicion he knew or should have known. The Madoff Trustee Irving Picard filed civil suits against him trying to recover more than $60 million Mark took from the firm. Picard alleges if Mark had done his job, Bernie Madoff's Ponzi scheme might not have succeeded for so long.
Officials point out the criminal investigation continues to move forward. Two more Madoff employees were recently charged and Madoff's right hand man Frank DiPascali has pleaded guilty and continues to tell all he knows.
"As other defendants who are arrested cooperate there is a very good chance that they may get enough information to prosecute him," McAvoy said. She pointed out complex white collar investigations often take years to complete.
Mark Madoff apparently did not want to face any more years of scrutiny.
Spokesmen for the US Attorney, FBI and IRS all declined to comment.
Mark Madoff was found Saturday morning in the living room of his $6 million apartment on Mercer Street in SoHo. A family member positively identified the body on Sunday, and the medical examiner confirmed the cause of death.
Madoff's wife, Stephanie, sent her stepfather to the couple's home after he e-mailed her at Disney World in Florida, where she was vacationing with their 4-year-old daughter. In the messages, he told her he loved her and that someone should check on their 2-year-old child, Nicholas, police said. He left no suicide note.
Saturday marked the two-year anniversary of the arrest of Bernie Madoff, who pleaded guilty to 11 federal crimes and admitted to turning his wealth management business into a massive scheme that defrauded thousands of investors of billions of dollars.