Renault chief Cyril Abiteboul has accused Red Bull's Adrian Newey of lying after he blamed the car's problems on the engine.
Recent four-time constructors champions Red Bull finished a lap down on Lewis Hamilton's Mercedes in the opening race of the 2015 season.
Technical boss Newey stated "we've got an engine which is quite a long way behind".
Lewis Hamilton's brother will become the first disabled person to race in the British Touring Car Championship.
Nicolas Hamilton, who has cerebral palsy, has joined the British AmD Tuning team and will compete in five races in an Audi S3.
The 22-year-old told 5 live Sport he is "a Paralympian racing in the Olympics" adding "there's no one doing what I'm doing in terms of disability".
Fernando Alonso will return to racing at this weekend's Malaysian Grand Prix, if he is given the all-clear by doctors, his McLaren team say.
The double world champion missed the season opener in Australia on 15 March to recover from concussion suffered in an accident in pre-season testing.
McLaren said in a statement Alonso, 33, felt his steering go heavy before the crash, which is so far unexplained.
Valtteri Bottas is confident of racing in Malaysia at the end of the month after missing the first grand prix in Australia because of a back injury.
The Finn, 25, was told he could not compete after suffering a small tear in an annular disc during qualifying.
"Progress is made and every day is a step forward. Can't wait for Malaysia," tweeted the Williams driver.
The German Grand Prix has been cut from the Formula 1 calendar for 2015, leaving just 19 races on the schedule.
Hockenheim hosted the event in 2014, won by Nico Rosberg, but is supposed to alternate with the Nurburgring.
However, the Nurburgring has changed ownership and baulked at paying the hosting fees for the 19 July race.
