Jason LaVeris / FilmMagic via Getty Images, file

Duane "Dog" Chapman and his wife Beth Smith said in a statement that they were "taking these threats seriously."

Death threats against TV bounty hunter Duane "Dog" Chapman and his family are being probed by the Federal Bureau of Investigation, according to reports.

The threats were emailed to the Chapmans over a four-day period, sources close to the family told Hawaii News Now.

The emails, which were published in full by Radar Online, contain graphic and disturbing content involving sexual violence aimed at Chapman’s daughters.

'In cold blood'
The site said Hawaii-based Chapman, who is known as "Dog the Bounty Hunter" and stars in a reality show on A&E, received an email on April 30 which read: "I'm going to murder you. I'm going to come to Hawaii and murder you and your family in cold blood. You are next on my list and are the bane of society. I will deliver you to God."

Another email reportedly said: "I have a rather nasty vendetta against you and your family."

Hawaii News Now reported the Los Angeles FBI field office referred the case to the Honolulu FBI field office. However, authorities said they were unable to confirm or deny the existence of any investigation unless or until any charges were filed.

In a statement, the Chapman family said they were "taking these threats seriously."

More content from msnbc.com and NBC News:

• Chicago braces for major protests as NATO summit looms
• 'Green Team' kids urge Crayola to recycle plastic markers
• Estranged Kennedy wife died from hanging
• Video: 250-pound alligator chomps man's arm
• Immigration decision a plus for Klezmer tango band

Follow US News on msnbc.com on Twitter and Facebook