A shocking and disgusting email sent to NASCAR legend Greg Biffle just hours after his death has been revealed as police continue an investigation into the burglary of his home.

Tragically, Biffle, his wife Cristina, and two children, Emma and Ryder, died in a plane crash on December 18 last year when their jet attempted to reland at Statesville Regional Airport in North Carolina.

Seven people died in the crash in total, with Dennis Dutton, his son, Jack, and Craig Wadsworth also killed.

Just over a month later, though, a shocking development occurred, with police revealing that burglars had stolen thousands of dollars from the Biffle family home following their death, as well as NASCAR memorabilia and two Glock handguns.

NASCAR TODAY: Kyle Busch warning sent and Stephen A. Smith hits back at Cup Series champion

Greg Biffle burglary investigation continues

Since then, the investigation by the Iredell County Sheriff’s Office has continued, and recently, the police have executed search warrants, the filings for which revealed shocking further details.

WSOC-TV has obtained the search warrants and reported that while the burglary took place on January 8, suspicious activity surrounding the Biffle family began almost immediately after their deaths.

This included a shocking email that investigators say was sent to Greg Biffle's email address at 2 a.m. on December 19, which read: “I heard you’re dead, rest in hell.”

On that very same day, the warrants state that information linked to bank accounts belonging to Biffle and his wife, Cristina, including email addresses, phone numbers, and passwords, was changed, while there was also fraudulent activity detected on Cristina's Venmo account.

READ MORE: NASCAR legend Jimmie Johnson makes controversial retirement reveal

Hundreds of thousands stolen

While initially it was revealed that $30,000 in cash had been stolen from Biffle, reports that have seen the warrants state that investigators put the figure in the hundreds of thousands if you include the fraudulent activity on their accounts alongside the burglary cash.

Last week, it emerged that there was a person of interest in the case, but it appears the investigation is not honed in on just one individual at this stage.

“There are multiple suspects over multiple states," Iredell County detectives told WBTV.

"We can’t say they’re not connected, but we’re still investigating."

The aforementioned search warrants were executed at a home in Lincoln County and a business in Mooresville, as per WBTV, with no items from the burglary found at either address.

However, several electronic devices were seized as evidence from a search at a home in Denver (North Carolina), with the Iredell County Sheriff’s Office now seeking additional search warrants for those devices.

Oval Insider has contacted the Iredell County Sheriff’s Office for comment.

READ MORE: Jason Kelce recalls 'awesome and terrifying' 190mph NASCAR ride after HMS win