The row over the Mercedes car took a new twist as Max Verstappen and Lewis Hamilton were third and fifth fastest in pre-season testing.
The Mercedes design complied with the rules after being quoted saying it was illegal, according to the Red Bull team principal.
It looks like it ticks all the legality boxes, but it was an extreme rules interpretation.
He insisted that his earlier quotes about the car were not made.
The first two days of testing ended with Verstappen 0.13 seconds quicker than Hamilton.
A number of senior figures stressed that it was not possible to accurately judge form from testing, as the world champion trailed Carlos Sainz of Ferrari by 0.478 seconds.
Kevin Magnussen set a faster time than Sainz in the extra hour his team was allotted to make up for time they lost on Thursday due to a freight delay.
The new season starts at the same track next weekend, but there is only one day of testing left on Saturday.
The aerodynamic upgrade to the car that first ran at the opening test in Barcelona was unveiled at the start of the Bahrain test.
The upgrade features side-pods that are smaller and aerodynamic wing sections with wing mirrors mounted on them.
According to Germany's Auto Motor und Sport, Mercedes have introduced a new design at this week's final pre-season test inBahrain, which has raised doubts about its legality.
Those are not mirror mounts, but two wings. They have built vertical baffles. The mirror mount has nothing to do with them.
From our point of view, Mercedes has gone too far. That doesn't correspond to the spirit of the regulations. These wings are not legal for us.
Red Bull initially said the quotes were incorrect, before clarifying that they were not official.
The journalist in question is a veteran reporter named Michael Schmidt.
At the news conference on Friday, he was asked about the contradiction in his position.
He said that the comments had not been made. The car is innovative and it is an interesting solution. The Mercedes car is in compliance with the regulations. It is a different interpretation and a different solution.
There isn't anything that defines the spirit of the regulations, it either complies or it doesn't. That is not something we can judge.
The FIA have access to all of the drawings. It would have been submitted in advance. It is an interesting concept and a radical one. Is it quick or not? In terms of its compliance, that is very much an FIA matter.
It was impossible to tell which teams were in the best shape.
When people run as fuel comes out, you will get the first snapshot, he said.
I don't think Mercedes have shown their hand yet. The team looks good. Hopefully we can be there as well. It looks like McLaren has a strong car. Alpine have a strong car.
Hamilton said it was a tough day for Mercedes, and that the team were still struggling with the aerodynamic problem they experienced at the first test.
He said that it looked like Ferrari were in good shape.
George Russell claimed that Mercedes looked in the best shape so far.
The Spaniard said that it was typical of Mercedes to hype up the others and then come to the first race and blow the competition away.
If it was the first season they did it, I would believe them, but they have done it for five, six years now and they keep surprising us in the first race. I don't believe much.
The analysis of the gps speed traces available to all the teams suggested that Mercedes were very competitive.
He said that we can see what they are doing in the gps app.
McLaren admitted that they had a front brake problem that required new parts before it could be fixed.
Lando Norris was forced to drive again after Daniel Ricciardo missed a second day of running because of illness.
The Australian has tested positive for Covid-19 and will miss the final day.
McLaren said in a statement that Ricciardo was isolating in accordance with local regulations.
The team said that Daniel would be released in time for the race. Daniel is starting to feel better.
Before he can race in the season- opening race, he will have to return a negative test.
Williams missed most of the day after a fire in the rear brakes caused Nicholas Latifi to spin off during the morning session and there was a failure at the rear as the fire was extinguished. The team couldn't get out again.
Kevin Magnussen is one minute 33.207 seconds.
Carlos Sainz is in 1:33.532 seconds.
Max Verstappen is a Red Bull athlete.
4 Lance Stroll (Can)
Lewis Hamilton is with Mercedes.
6 Esteban Ocon is from France.
Charles Leclerc is from Monaco.
Lando Norris has a McLaren.
Sebastian Vettel is from Germany.
Alpha Tauri by Yuki Tsunoda is 1:36.802.
Valtteri Bottas is a driver for Alfa Romeo.
Mick Schumacher (Ger) has a time of 1:37.846.
George Russell has a Mercedes.
Nicholas Latifi had a 1:39.
15 Zhou Guanyu (Chi) Alfa Romeo.
The C4 and C2 are the same tire. All times on C3. C5 is softer than C1.