The Swiss Federal Office of Justice (FOJ) had said earlier on Friday that one of those detained had agreed not to fight extradition but it did not identify the official.
The source, speaking on condition of anonymity, confirmed to Reuters that Webb, a former FIFA vice president and president of the CONCACAF regional soccer federation, was the official concerned. Bloomberg News first reported that Webb, a citizen of the Cayman Islands, was the person.
A U.S. lawyer for Webb declined to comment.
Without identifying Webb, the Swiss FOJ said that a transfer of the person would take place within 10 days. A spokeswoman for U.S. prosecutors in Brooklyn, New York, declined to comment.
Webb was one of the powerful figures arrested in Zurich on May 27 two days before FIFA’s annual congress, stunning world soccer.
An indictment unsealed by U.S. prosecutors in Brooklyn charged soccer officials and marketing executives with exploiting the sport for their own gain through bribes of $150 million over 24 years.
The scandal put pressure on FIFA President Sepp Blatter, who said on June 2 he planned to resign.
Webb is charged with racketeering conspiracy, wire fraud and money laundering. He has been provisionally banned from his posts at FIFA and CONCACAF.
The U.S. indictment describes Webb as using his influential positions to solicit bribes from sports marketing companies in exchange for the commercial rights to soccer matches.
One $500,000 bribe payment from a sports marketing firm called Traffic went to build a swimming pool at Webb’s house in Loganville, Georgia, the indictment charged.
Last week, Cayman Islands officials announced separate charges against Webb in an unrelated healthcare fraud case.
U.S. prosecutors say their investigation – which is running parallel to a separate Swiss inquiry – exposes complex money laundering schemes, millions of dollars in untaxed incomes and tens of millions in offshore accounts held by FIFA officials.
The United States last week filed extradition requests for the seven officials.
The other six were Eugenio Figueredo, Eduardo Li, Jose Maria Marin, Julio Rocha, Costas Takkas and Rafael Esquivel.
(Reporting by Nate Raymond, David Ingram, Mica Rosenberg and Noeleen Walder in New York and by Michael Shields and Joshua Franklin in Zurich; Editing by Andrew Roche and Grant McCool)