Haas Formula 1 chief Günther Steiner has insisted the team's relationship with technical partner Ferrari is "well above board" despite facing criticism from rivals about the development of its car.

Haas made a flying start to the new season as Kevin Magnussen and Romain Grosjean started fifth and sixth respectively in Melbourne, and were poised to record a double-top-five finish before a pit stop issue forced both drivers to retire from the race.

Haas' pace turned heads up and down the paddock, with figures from both Force India and McLaren querying the design of the VF-18 car given the team's public technical partnership with Ferrari.

McLaren's Fernando Alonso said the new Haas was a "replica" of Ferrari's 2017 car, while Force India officials Andrew Green and Otmar Szafnauer said they wanted clarification from the FIA over the aerodynamic similarities allowed between cars.

Responding to the comments ahead of next weekend's Bahrain Grand Prix, Haas team boss Steiner said the claims were baseless and that the American squad was doing nothing forbidden by the regulations.

"Everybody is allowed to have an opinion. Some people have an opinion, which I think is based on no facts," Steiner said.

"It does not have a lot of value to me. I think the whole of Haas F1 Team can be proud of the work done between last year and over the winter to produce the VF-18 and get it into its competitive condition. It’s merit to them. They can be proud.

"If people have an issue, fine with me. We report what we are doing, like everybody else, to the FIA. That’s why I’m more than confident we are not doing anything wrong.

"I’m perfectly fine with how we do business. We design our own aero, as per the regulations, and yes, we use mechanical parts from Ferrari, but everybody’s known that for the past two years.

"We are well above board, and happy to be where we are.”