That’s according to BBC reporter David Ornstein.
Arsenal have been pursuing the Saint-Etienne defender all summer.
But it appears their biggest rivals Tottenham have swooped in at the 11th hour to steal a march on Saliba.
According to Ornstein, the Gunners were in the final stages of landing the 18-year-old before Tottenham trumped their offer.
The respective lawyers of both parties were also putting the final touches on the contracts.
But Mauricio Pochettino’s side have bid €30m (£26.8m) plus bonuses for Saliba’s signature, which goes well above Saint-Etienne’s valuation of the central defender.
Arsenal are said to have only bid around £20m for the Frenchman, who was set to be loaned back to the Ligue 1 outfit for another season.
Spurs first made Saliba aware of their interest in June.
RMC reported that the Champions League runners-up were preparing their first offer for the defender but still faced a tough task beating Arsenal to his signature.
Saliba’s Saint-Etienne exit nows looks almost certain.
But club officials recently suggested they weren’t prepared to let the prospect leave easily.
“Our accounts are balanced, so there’s no imperative need to sell him,” chairman Bernard Caiazzo told French outlet But!
“We know there are solicitations and that his future will be via a top European club, but there’s no rush.
“He will stay this season.
“That’s an imperative condition if we are to find an agreement for his transfer.
“We’ve clearly defined the conditions.
“It’s also William’s wish. He wants to wear the green shirt this season, to play in the Europa League, and he wants to get better before leaving.”
Tottenham have already signed Jack Clarke and Tanguy Ndombele so far this summer.
Arsenal’s only new arrival comes in the form of young attacker Gabriel Martinelli.