The US Secret Service is to investigate the hacking of Fox News' political Twitter account over updates claiming the President was dead.

A series of six tweets coming from the FoxNewsPolitics account reported that Barack Obama had been shot to death in Iowa and the shooter was unknown.

In a statement posted on its website later, Fox News called the tweets "malicious" and "false."

Secret Service spokesman George Ogilvie says the law enforcement agency whose job it is to protect the president will conduct a probe of the false postings and that "we will conduct the appropriate follow up."

An online magazine at New York's Stony Brook University, Think, reported that initial posts around midnight indicated the Fox News Twitter account had been hacked by a group called the Script Kiddies.

Harmless posts announcing the group's hacking of the Fox News account were followed by the false posts about Obama, according to Think.

A Think staffer, Adam Peck, wrote on the magazine's website that he had exchanged electronic messages with a person claiming to be with the Script Kiddies shortly after the initial hacking.

Later, however, the unidentified person would not confirm that the group was behind the Obama posts, Peck wrote.

Fox's political Twitter account has more than 34,000 followers.