While Harry Truman once advised, "If you want a friend in Washington, get a dog," a pup in Argentina is proving that dogs will be your friend in the afterlife too.

The dog, a German shepherd named Capitan, has loyally sat by his owner's grave for the past six years, rarely leaving the graveside of the man, Miguel Guzman, who adopted him as a gift for his teenage son in 2005.

Guzman died suddenly just one year later, in 2006, and when the family returned from his funeral, Capitan was gone, the UK's Daily Mail reports.

"We searched for him but he had vanished," Guzman's widow reportedly told a local newspaper, The Cordoba. "We thought he must have got run over and died."

When the family returned to the cemetery, which Capitan had never previously been to, just days later to visit Guzman's grave the dog was there.

"He [Capitan] turned up here one day, all on his own, and started wandering all around the cemetery until he eventually found the tomb of his master," the cemetery's director, Hector Baccega, told the newspaper. "During the day he sometimes has a walk around the cemetery, but always rushes back to the grave. And every day, at 6 o'clock sharp, he lies down on top of the grave stays there all night."

Staff at the cemetery, located in Villa Carlos Paz in central Argentina, are feeding and taking care of Capitan as their own and Guzman's son, for whom Capitan was adopted, says he doesn't think the dog will ever leave.

"I've tried to bring Capitan home several times, but he always comes straight back to the cemetery," said the son, 15-year-old Damian. "I think he's going to be there until he dies too. He's looking after my dad."