The family of a US student last seen in Palmerston North has called in a private investigator

William Henry Johnson was last seen by friends between May 30th and June 1st in the suburb of Takaro, and last contacted family on June 5.

The 24-year-old's Silver Mazda 6 is also missing.

Investigators New Zealand Director Mike Gillam says his disappearance is completely out of character, and his mother has flown to New Zealand to assist the search.

Gillam's urging anyone who's seen Will since May 30th, or has information on his whereabouts, to come forward.