People walk past a Citibank branch in Buenos Aires, Argentina, Feb. 19, 2016. REUTERS/Marcos Brindicci

U.S. authorities have decided not to pursue criminal charges against any Citigroup Inc. executives or employees involved in packaging and selling mortgage-backed securities at the heart of the 2008 financial crisis, a government report shows.

The decision, which followed Citigroup's $7 billion settlement in 2014 resolving federal and state civil claims related to mortgage bonds, was described in a November report obtained by Reuters in response to a Freedom of Information Act request.

Its release marked the first public acknowledgement by U.S. authorities that executives at a major bank linked to the financial crisis would face no criminal charges for their involvement in selling billions of dollars in toxic mortgage bonds.

The report, by the Federal Housing Finance Agency's Office of Inspector General, one of the agencies in the Citigroup probe, said following the settlement that prosecutors reviewed the evidence to see if any individuals could be charged, and determined "there was not enough compelling evidence."

The investigation focused on the bank's practices related to its sale and issuance of mortgage bonds from 2006 to 2007.

The two-page report, which summarized the investigation and called the probe closed, does not name any individuals who were investigated, nor does it elaborate on why individuals could not be successfully prosecuted.

Patrick Rodenbush, a U.S. Justice Department spokesman, in a statement noted the department in September announced a new policy that "emphasizes the priority in any corporate case of holding individual wrongdoers accountable."

He declined to say, though, if individuals at any other banks investigated for practices related to mortgage-backed securities remained under investigation. The status of any such probe is unknown.

A Citigroup spokeswoman, Danielle Romero-Apsilos, declined to comment Friday, and a spokeswoman for the FHFA Office of Inspector General did not respond to a request for comment.

The review of the evidence in the Citigroup case for potential actions against individuals was conducted by the U.S. Attorney's Office in Colorado, one of two such offices involved in the investigation.

According to the report, the review came at the request of the Justice Department, which asked that all mortgage-backed-security settlements reached with the government be reviewed to determine if individuals could be held personally responsible.

Those settlements include a $13 billion accord with JPMorgan Chase & Co. in 2013 and a $16.65 billion deal with Bank of America Corp. in 2014. Most recently, federal and state officials announced $3.2 billion in settlements with Morgan Stanley on Feb. 25, which, when combined with a series of related resolutions, resulted in $5 billion in settlements with government agencies.

The Goldman Sachs Group Inc. in January announced it had reached an agreement in principle to pay over $5 billion to resolve federal and state claims.

The Justice Department has faced years of criticism for failing to prosecute banking executives over conduct leading up to the financial crisis, even while it secured billions of dollars in settlements with big banks.

The government cases came out of a task force formed by President Barack Obama in 2012 to probe misconduct that contributed to the financial crisis.

Obama said he was creating the group to "hold accountable those who broke the law" and "help turn the page on an era of recklessness."

In February 2015, then-Attorney General Eric Holder said he had given federal prosecutors a 90-day deadline to develop cases against individuals related to mortgage bonds and report back if they could be successful.

Despite that push, no such cases have emerged to date.

In the case of Citigroup, the $7 billion settlement explicitly did not release individuals at the bank from criminal or civil charges, or the bank itself from potential criminal prosecution.

During the probe, authorities gathered 25 million documents related to mortgage securities, obtained internal bank emails and documents, and interviewed current and former employees and executives, the inspector general report said.

"The totality of the evidence and testimony obtained showed that Citigroup knowingly and purposefully purchased and securitized loans that did not meet representation and warranties or in many cases were outright fraudulent loans," the report said.