Updated

FBI agents on Friday visited the suburban Washington home of former CIA Director David Petraeus, who resigned last year after revelations about an extra-marital affair, according to several news reports.

An FBI spokeswoman told Fox News on Saturday she could confirm only that there was "law enforcement activity in Northern Virginia."

Agents went to Petraeus’ home to interview him, but it's not clear whether he was home, according to USA Today.

Officials are saying the visit is part of the ongoing investigation into allegations that Paula Broadwell, with whom Petraeus had the affair, improperly received or stored classified documents while writing his biography, sources told NBC.

Agents have also visited Broadwell’s home in Charlotte, N.C., that she share with her husband and two children.

The affair was exposed in November as part of an investigation into threatening emails Broadwell, 40, purportedly sent other women, Tampa, Fla., socialite Jill Kelley. Petraeus, 60, resigned weeks later and publically apologized earlier this month.