MOORESVILLE, N.C. — Sheriff’s deputies are investigating an alleged break-in and theft last week at the North Carolina home of retired NASCAR driver Greg Biffle, one of seven people who died in a plane crash last month.

The alleged burglary and forcible entry into the Biffle home in Mooresville was reported last Thursday, according to an incident report from the Iredell County Sheriff’s Office.

Sheriff Darren Campbell said Wednesday that investigators believe someone entered a safe in the home. In addition to $30,000 in cash and a backpack identified in the incident report as stolen, Campbell said some guns and memorabilia also are gone.

Campbell said that no arrests have been made and that no one else was in the home at the time of the alleged crimes. The incident report said the home was last known secure the afternoon of Jan. 7.

“We’re working the case. We are waiting on some digital evidence,” Campbell said, adding that interviews also were being conducted.

A business jet carrying Biffle, Biffle’s wife and two children and three others crashed Dec. 18 while trying to return to an airport in Statesville — located about 45 miles (72 kilometers) north of Charlotte — minutes after taking off from there.

Federal investigators said the Cessna C550 erupted into a large fire when it hit the ground short of the runway. Everyone on board died.

No cause of the crash has been disclosed. Biffle was one of three people on board with a pilot’s license. Investigators said during the crash’s immediate aftermath that they didn’t know who was the lead pilot on the flight.

A public memorial service for Biffle, who won 19 NASCAR Cup Series races over his career, and the six others killed is scheduled for Friday morning at a Charlotte arena.