Mercedes confirm cause of Hamilton's Melbourne mix-up

Mercedes have confirmed that an "offline tool" lumped them with the dodgy data which allowed Sebastian Vettel to pip Lewis Hamilton under the Virtual Safety Car an win the Australian Grand Prix. The Silver Arrows pit wall were baffled as to how Vettel was able to sneak ahead when a furious Hamilton took to his radio.

Team boss Toto Wolff put the error down to a "software bug" immediately after sunday's race at Albert Park after Hamilton's race engineer Pete Bonnington could only offer to a frustrated world champion during the race: "We thought we were safe, but there's obviously something wrong."

Vettel extended his opening stint on Sunday after Hamilton and Kimi Raikkonen pitted from P1 and P2 and the German managed to maintain the lead under VSC, brought out by Romain Grosjean's retirement on lap 25.

After locking up his brakes in his attempts to gain first place back from Vettel, Hamilton soon backed off to save engine life for a long season ahead with only three power units available.

The constructors' champions have now revealed that a pre-set tool used to determine how much of a gap they would need to Vettel caused the misunderstanding.

"The issue isn't actually with the race strategy software that we use," Mercedes trackside engineering director Andrew Shovlin told Pure Pitwall.

"It was an offline tool that we create these delta lap times with, and we found a bug in that tool that meant that it gave us the wrong number.

"The number that we were calculating was around 15 seconds, and in reality the number was slightly short of 13 seconds, so that was what created our delta.

"That is why we thought we were safe. We thought we had a bit of margin and then you saw the result.

"We dropped out, we were in second place and it is very difficult to overtake and we couldn't get through.

"It is really about understanding everything that went wrong, gathering all the data, and invariably it is never just one thing.

"So there are elements that we can do better with calculating that, but we have also looked at it for future.

"We are going to make sure we have more margin because we want to be able to cover for Vettel doing an amazingly good inlap to the pits, or having an incredibly fast stop.

"So with any of these things, we look at what went wrong, work out how to solve it and then put the processes in place to make sure we don't have a repeat."