Zak Brown makes unusual Red Bull staff demand despite FIA declaring investigation 'closed'

has requested that the senior leadership and garage circles 'sign an affidavit' stating that they have never used the bib at the centre of the investigation at the .

Heading into the weekend, the presence of a bib device in the Red Bull cockpit generated massive controversy. If it was ever used in Parc Ferme conditions to adjust the ride height of the RB20 then the Milton Keynes-based team would have committed an infringement of the regulations.

The FIA have addressed the issue and Red Bull insisted that they have never used the device in Parc Ferme conditions, but McLaren Racing CEO Brown is not content.

"I'd like to see the senior leadership, the former chief mechanics and the current mechanics sign an affidavit stating that they have never used or have no knowledge of it being used," he told the .

"The suggestion in the pit lane from a handful of people is that it has been used in that manner, so the only way to bottom it out is the old-fashioned 'sign here', stating what has gone on. I know if I was presented with an affidavit and the consequences of not telling the truth were severe, I'd tell the truth."

If Brown wants to get the affidavit he craves, Red Bull will have to volunteer it. The FIA are unlikely to get involved, having declared the matter "closed" after receiving a live demonstration from engineers on Friday.

"I mean, honestly, can I say with complete certainty about whether there's ever been anything irregular? No," explained FIA head of single seaters Nikolas Tombazis. "Can I say that the matter is closed? Yes, absolutely."

Red Bull team principal Christian Horner doesn't believe his team did anything wrong. "I think there's been a bit of moaning from one of our rivals," he told Sky Sports F1 on Saturday.

"And it's the FIA's job to look into these things. It's on a list of the open-source components, so it's been publicly available for the last three years. The FIA are happy with it, I think, just to satisfy perhaps some paranoia elsewhere in the paddock."

Horner then went a step further, pointing the finger back at Brown and . "I feel that it's sometimes to distract from perhaps what's going on in your own house," he teased. "Then sometimes you try to light a fire somewhere else."