Multiple “fraudulent activities” were committed against late NASCAR star Greg Biffle shortly after he died in a North Carolina plane crash. Investigators say friends of the driver stole money from him through various online accounts.

Biffle, his wife and children were killed when their Cessna C550 crash landed near Statesville Regional Airport on Dec. 18 last year, which allegedly triggered a digital looting of the Hall of Fame nominee's accounts, according to a search warrant affidavit.

"Multiple fraudulent activities were discovered during the course of this investigation. Banking accounts, Venmo accounts, PayPal accounts, and other financials were accessed by an online suspect," Iredell County Sheriff’s Detective Charles Davidson wrote in a search warrant affidavit.

"Personal information of Greg and Christina Biffle were used to change phone numbers and email addresses in order to access funds within these accounts. The funds were transferred to other accounts not owned by Greg or Christina Biffle as well as used to make multiple purchases."

Investigators believe a break-in at the Biffle residence on the night of Jan. 7 and early morning of Jan. 8 helped suspects gain access to the driver's accounts.

A woman was captured on security video spending nearly six hours inside the Biffle home before “leaving with multiple bags,” according to the search warrant application.

"This affiant believes this personal information was taken from the Biffle residence during the breaking and entering of the estate," Davidson wrote.

The detective said he believes the woman and her husband are friends of the Biffle family.

The search warrant sought permission to enter a Mooresville, North Carolina property connected to the woman and her husband.

There have been no arrests made so far.

"This remains an active and evolving investigation, involving multiple sources of information and a substantial body of evidence from across the country," Iredell County Sheriff's Attorney Adam Dillard said in a statement to NBC News Friday night.

"We are analyzing data and working with our federal partners in hopes that we can get a resolution for the families involved in the near future."

The sheriff's office is still appealing to the public for help, "asking for anyone with information about the break-in or alleged bank fraud to contact us" at (704) 878-3180, Dillard added.

Meanwhile, newly uncovered documents also showed that at least two estates of fellow victims on board that doomed flight filed wrongful death claims against Biffle's estate, claiming the former racer was at fault for the tragic crash.

The estates of Dennis Dutton and Jack Dutton are each seeking at least $15 million after they accused Biffle, the plane’s owner, of failing to properly care for the craft.

While Biffle was an experienced pilot, it was retired Delta pilot Dennis Dutton who was at the controls, officials said. Dutton's son Jack was also a licensed pilot.

Biffle "through his sole control" of the plane's ownership entity, GB Aviation Leasing, "had a duty to use reasonable care in the operation, use and maintenance" of the doomed Cessna, according to the April 17 civil claims.

While the NTSB has yet to issue a final report or assign any human error responsible for crash, the civil actions listed a host of allegations against Biffle and his alleged failure to keep the plane safe.

Reps for Biffle's estate could not be immediately reached for comment on Friday.