Red Bull could be reportedly penalised after it emerged they might have breached budget cap rules alongside Aston Martin.
Lewis Hamilton missed out on securing his eighth title in a dramatic final race in Abu Dhabi last season as he lost out to Max Verstappen.
According to a report in German newspaper Auto Motor und Sport, Red Bull could have broken the cap by around $5million (£4.5m) in 2021.
Red Bull has claimed the reports are "just speculation at this stage" with Aston Martin revealing they were "in discussion with the FIA".
The FIA said there will be no further comment from the governing body until a formal process has been concluded. It is claimed Mercedes and Ferrari feel the extra spend could have contributed up to half a second in track performance.
Rivals call for maximum penalty
Red Bull's rivals will likely be pushing for the maximum penalty to set a precedent and stop other teams from breaching the regulations, the report added.
According to the existing rules, a material breach of more than five per cent of the cap could result in tough sanctions. This includes the possibility of constructors' and drivers' points being docked and possibly teams being suspended from races.
However, this is unlikely to result in Lewis Hamilton being promoted to world champion. Although sanctions do include loss of Drivers' Championship points, the FIA would probably be more likely to only dock the teams' standings if the breach was deemed significant enough.