Valtteri Bottas and Charles Leclerc defended themselves Thursday after choosing to leave the Formula One "bubble" for time at home in Monaco ahead of this weekend's Styrian Grand Prix.

The pair are under investigation by the sport's ruling body the International Motoring Federation (FIA).

The Finn, who won last Sunday's season-opening Austrian Grand Prix at the same bio-secure Red Bull circuit, and Leclerc, who finished second for Ferrari, were back at the arena to fulfill news media commitments.

Leclerc had been pictured posing with a restaurant waiter without social distancing or protective masks, raising concerns about a breach of F1's strict Covid-19 protocol.

He admitted that he had flown home, but said he had since returned two negative test results while Bottas said he had been given approval for his travel plans in advance.

Bottas said his plans were approved and insisted that it was "a good decision."

"I think it was a good decision and from a safety point of view there's no difference at all – it's still the same people that I would be with here."

Under new rules, all F1 personnel are required to remain within their so-called "bubbles" between races.

Bottas' bubble includes girlfriend Tiffany Cromwell and trainer Antti Vierula. 

A spokesperson for Bottas' Mercedes team said: "Valtteri remained in his bubble and maintained Covid testing protocol, being tested in Monaco on Tuesday and again today at the track."