Dubbed “the most heartless couple in the US”, an American husband and wife from Trenton, Michigan have sparked worldwide outrage for their despicable cyber-bullying of a dying 7-year-old girl.

The victim, third-grader Kathleen Edwards, is battling Huntington’s disease. The incurable disorder, which destroys the mind and makes patients lose control of their bodies, also took the life of Kathleen’s 24-year-old mother, Laura Edwards, last year.

Jennifer Petkov, 33 and her husband, Scott were lambasted for posting a photo of the terminally-ill schoolgirl on Facebook above a set of crossed bones.

And that’s not all. In yet another incredibly cruel taunt, Mrs Petkov also put a picture of the girl’s dead mother in the arms of the Grim Reaper online. The pictures have since been taken off Facebook.

After Laura Edwards’ tragic death last year, the Petkovs also allegedly drove their truck – which bears the message “Death Machine” on its side – down the street and honked the horn. American news outlet CBS News reported the truck had been painted to look like a hearse.

A Facebook page has since been set up by angry members of the public, calling Jennifer Petkov the “Devil of Detroit Street”. An online petition, which describes the couple as “disgusting human beings”, aims to collect 100,000 names.

Messages of support for the family have poured in from around the world including Britain and Germany since the story went viral.

See the interview of the couple here.