Daniel Ricciardo says he will be seeking clarity from F1 race officials regarding the virtual safety car procedure after losing out to Nico Rosberg during a restart in Austin.

In the initial virtual safety car period at the Circuit of the Americas Ricciardo had built up a handy advantage over Rosberg in third place having passed the pole sitter in the opening laps.

Under the new virtual safety car regulations introduced 12 months ago every car is required to stay within a minimum time set by the FIA in each sector of the track and, theoretically at least, maintain the same time gap between each car on track.

However, during the first virtual safety car period the pack bunched up behind race leader Lewis Hamilton and upon the return to green Rosberg was close enough to blast back past the Red Bull driver.

Ricciardo says he was bemused by the incident and will seek guidance from the Formula 1 race officials to understand what the problem was.

"I came on the radio and asked how did Nico pass me because theoretically you should keep the same gap you had under the virtual safety car," Ricciardo said. "Then all of a sudden Rosberg caught us and I don't know how under the safety car.

"I don't think it was clear today when the virtual safety car period was over so I think we can definitely make it better because it either caught me out or Nico jumped. It was a bit strange."