After disputes over luxury camper vans and brickbats over panelling around their warm-up area at time trials, Team Sky faced accusations over marginal gains from two rival teams on Sunday.

La Française des Jeux made representations to the race referees and a coach at BMC Racing talked to journalists about concerns the British squad had gained an unfair advantage thanks to an aerodynamic skin suit which it was claimed was against the rules. The team responded that the outfits have been validated by the Union Cycliste Internationale and the race referees stated publicly that there was no case to answer.

The skin suit includes panels incorporating small pellets which improve the air flow by creating tiny vortexes as the cyclist travels through the air. The dispute is over whether or not the pellets are an integral part of the material. The rules stipulate: “Garments must not be adapted in any way that they diverge from their use purely as clothing. The addition of any non-essential element or device to clothing is prohibited.”

Fred Grappe, the sports scientist who works with the FDJ team, said: “The rule is very clear. Any aerodynamic addition to the jersey is banned. Sky have clearly infringed.” But the race jury president, Philippe Marien, told the Reuters news agency that the pellets are “an actual part of the jersey”. He said: “We summoned the team’s sports directors to check the jerseys. Nothing was added to them.”

Nicolas Portal, the Team Sky sporting director, said: “Everything is legal and the equipment was validated by the race commission. We wouldn’t have taken the risk of losing the Tour from the first stage by cheating. We haven’t cheated. We’re not infringing the rules because the vortex isn’t added to the jersey, it’s part of it – that’s different.”

Asked by a journalist whether he had used the skin suit before and whether it did indeed make him go faster, Geraint Thomas’s initial response was “you can borrow [one] and see what time you do”. Questioned a second time, the yellow jersey and first-stage time trial winner conceded that he had indeed used it at the Giro d’Italia.