Hackett hangs with US swim royalty

Grant Hackett has been spending time catching up with old friends in the United States.

The Olympic gold medalist posted a happy photo of himself in a car with swimming legend Michael Phelps.

The pair were joined by Phelps' wife Nicole, their son Boomer, and Olympian and mental health advocate Allison Schmitt.

Grant's mother told News Corp she still believed her son intended to go to rehab following his arrest on the Gold Coast last month.