Formula One: Lewis Hamilton, Nico Rosberg Crash Out in Spanish GP Clash

Formula One World championship leader Nico Rosberg and his Mercedes teammate Lewis Hamilton collided and retired in a sensational crash on the opening lap at Sunday's Spanish Grand Prix.

The two were scrapping for the lead and came together in a fashion that wrecked Mercedes' hopes of another one-two triumph and revived the bitter memories of their collision in the 2014 Belgian Grand Prix.

"We have spoken to both drivers and it is not a clear cut decision - we have lost 43 points after lots of effort by the team in the last few difficult weeks," said a strained Toto Wolff, the team chief.

Non-executive director Niki Lauda said: "It is stupid. We could have won this race Lewis was too aggressive.

"I need to talk to them myself, listen to the explanations, and then we will see."

Wolff said Lauda's comments were the instant emotional reaction of a former driver.

"We have to see all the data and take a considered view," he said.

Defending three-time champion Hamilton took the lead from pole position, but was passed at Turn One by the German, who took the initiative with a sweeping pass round the outside.

Briton Hamilton then gained speed on his run from Turn Three and attempted to pass inside Rosberg at Turn Four where, in defence of his position, the German driver 'closed the door' and forced his teammate onto the grass.

Hamilton then lost control and went into a spin and as his car slewed back across the circuit he clipped Rosberg, taking the pair of them off into a gravel trap less than 30 seconds into the race.

A furious Hamilton hurled his steering wheel out of his car after he came to rest and then slumped with his helmeted head in his hands.

Both men were unhurt and climbed from their cars to learn quickly that the stewards would investigate the accident after the race.

A Safety Car was deployed immediately and the field ran behind it for three laps before racing resumed, with Daniel Ricciardo of Red Bull in the lead ahead of his teammate Dutch teenager Max Verstappen.

As the two Mercedes drivers were taken back by scooters, their collision divided opinion in the paddock where emotions ran high in the Mercedes garage.

Hamilton was distraught in the knowledge that he had thrown away a chance of claiming his first victory in eight races since he won his third title in Texas last year.

In that period, Rosberg has won all seven races and taken a dominant lead in this year's championship while Hamilton, having suffered a series of misfortunes including two other first lap collisions and two engine failures.

The accident was witnessed by several of the Mercedes board's senior directors, who had flown in for the race.

It ended Rosberg's run of four wins this season and seven in all, dating back to last year, but did nothing for Hamilton's effort to close the 43-points lead that the German retained ahead of him.

It also revived memories of their acrimonious scraps in the last two years during which Hamilton has won two world titles and previous opening lap collisions involving championship contenders and team-mates Alain Prost and Ayrton Senna of McLaren-Honda in the past.

Both men returned to the paddock with their helmets on and refused to speak to reporters.