McLaren have succeeded in luring top aerodynamicist Peter Prodromou away from Formula One world champions Red Bull, team principal Martin Whitmarsh said on Saturday.
"He's signed a contract with us," he told Reuters at the Japanese Grand Prix, without giving any details about when he might start.
Red Bull team boss Christian Horner indicated McLaren could expect a long wait before Prodromou, head of aerodynamics in Adrian Newey's design team, would be free to return to his former employers at Woking.
"The contents of any contract will be confidential between the company and the individual," Horner told Reuters.
"We've enjoyed a long relationship with Peter and he's a valuable member of the team and there's quite a duration left on his contract.
"We won't force him to stay, if it's his choice to leave then he'll leave at the end of his contract. But we are quite some way off that."
Horner, who could be celebrating Sebastian Vettel's fourth successive title for Red Bull on Sunday, would not confirm that Prodromou's current contract ran to 2015.
London-born Prodromou was McLaren's head of aerodynamics until 2006, having joined in 1991, when he followed Newey to Red Bull. Together, they have produced the cars that have won the last three drivers' and constructors' titles.
Whitmarsh had indicated at the Korean Grand Prix last weekend that some high profile technical signings were in the pipeline for former champions who have yet to finish on the podium this season.
"We've been recruiting in the technical team, strengthening that quite a lot. There have been quite a few new starters this year, there are some as yet unannounced that will be headline-grabbing when they get announced," he told reporters.
"So there are things going on. We have to look at ourselves as a team, from the top management all the way through, as well as our technical team, to ensure we return to winning ways as quickly as possible."