Kellermann was a senior vice-president of Freddie Mac and had been working for the company since 1992.
He was named acting CFO in September, when, along with Fannie Mae, its sister company, it was bailed out by the US government in an attempt to prevent it collapsing and damaging the already struggling US housing market.
Investigators from the US justice department and the Securities and Exchange Commission (SEC) have been investigating Freddie Mac over possible accounting violations in recent months.
However, a Freddie Mac spokesman said on Wednesday that the company "knows of no connections between this terrible personal tragedy and the ongoing regulatory inquiries discussed in our SEC filings".
Huge losses on housing investments had weakened both Freddie Mac and Fannie Mae's balance sheets and prompted the government to bail out the companies, costing American taxpayers nearly $200bn.
Fannie Mae's and Freddie Mac's dire financial straits played a key role in the US housing and global credit crisis.
John Koskinen, Freddie Mac's interim chief executive, called Kellermann's death a "terrible personal tragedy".
Timothy Geithner, the US treasury secretary, also issued a statement saying that the "treasury family" was "deeply saddened" by Kellermann's death.