Alpine team principal Otmar Szafnauer said he was "very confident Oscar signed with us back in November".

McLaren also believe they are in the right but are not commenting publicly.

The contract recognition board (CRB) was set up to adjudicate in disputes such as this. It is a group of lawyers whose role is establish which party has prior right to a driver.

Szafnauer said: "We will have the CRB decide which contract Oscar signed takes precedence and after that we will see where we go.

"Once we have all the info in front of us we will start looking at who will fill the open seat."

On their legal position, he said: "There are certain things that need to be in the contract [to secure Piastri] and I am confident they are in there."

Szafnauer refused to comment on whether Alpine would try to force Piastri to drive for them if they won the case or try to seek a financial settlement with McLaren.

"Once we have all the info in front of us we will start looking at who will fill the open seat," he said.

However, he drew a parallel with a similar dispute that involved Jenson Button in 2004. Button had wanted to leave British American Racing and signed for Williams.

But BAR took up an option on him, the CRB ruled in their favour and Button did not move. Szafnauer was with BAR at the time and when they became Honda two years later.

Button later won his first race with Honda in 2006, and then the World Championship in 2009 with the same team after they became Brawn following the car company's withdrawal at the end of 2008.

"It is the logical next step when you believe you have a valid contract with the driver and he wants to go somewhere else," Szafnauer said.

"I was there with Jenson Button when he wanted to go to Williams, but BAR won in the CRB and we had a great relationship with Jenson thereafter that culminated with a World Championship, albeit after Honda had left the sport."

The dispute led to a remarkable day on the Tuesday after the Hungarian Grand Prix, before F1's summer break.

Alpine had hoped to keep Fernando Alonso and farm Piastri out to Williams to gain experience.

But Alonso objected to the offer of only a one-year deal and negotiations stalled. In the meantime, Piastri and his manager the former F1 driver Mark Webber decided they had lost faith in Alpine and committed to McLaren instead.

Alpine put out a statement on 3 August saying Piastri would drive for them in 2023, only for the 21-year-old to say on Twitter an hour later that the statement was unauthorised and he would not be racing for the team.

Szafnauer said in a news conference at the Belgian Grand Prix on Saturday that he had informed Piastri of the decision before the announcement went out.

"I saw Oscar before we put out the release," he said. "He was in the simulator, so I went and found him and told him. He smiled and was thankful."

McLaren team principal Andreas Seidl, who was sitting next to Szafnauer in the same news conference, shook his head and smiled when he heard those remarks.

Asked why he did not get a quote from Piastri for the statement, Szafnauer said he and the team had wanted to act fast.

He said he learned that Piastri did not want to drive for them "from social media".

The situation has damaged Alpine's reputation in F1, as on the face of it not only have they misunderstood Alonso's determination to secure more than a one-year contract, but have also angered Piastri and Webber with their intentions for him.

Szafnauer said he and chief executive Laurent Rossi had "no regrets" about the situation but admitted there were "lessons to be learned".