Washington ? Federal authorities said Tuesday they arrested three people and foiled an international plot to smuggle into the United States a shoulder-fired missile that could shoot down a commercial airliner.

A British man was arrested in Newark, N.J., after agreeing to sell a sophisticated Russian SA-18 Igla missile to an undercover FBI agent posing as a Muslim extremist, according to a federal law enforcement official who spoke on condition of anonymity.

The arrest occurred Tuesday afternoon at a hotel near Newark International Airport, according to a second federal official. The man had just flown to Newark from London to close the deal, another U.S. official said.

Two other men, believed to be involved in money laundering, were apprehended about the same time at a gem dealership on Fifth Avenue in Manhattan, the second official said.

The arrests were the result of a cooperative investigation involving U.S., British and Russian authorities. More arrests were possible, authorities said.

The investigation began about five months ago when the Russians passed on to the FBI a tip that the arms dealer was shopping for weapons in St. Petersburg, Russia, said one law enforcement official. British officials, including the MI5 domestic intelligence agency, helped track the man’s whereabouts.

The understanding between the Briton and the undercover FBI agent who agreed to purchase the weapon was that the missile needed to be capable of bringing down a commercial airliner, the first official said.

The missile, which was inoperable, was built in Russia specifically for the sting operation and brought to the United States aboard a ship to make the deal seem real, officials said. The investigation included the expertise of the Bureau of Immigration and Customs Enforcement and the Secret Service.

The British suspect does not appear to be connected to a known terrorist group.

Authorities stressed that no specific, credible threat was connected to the alleged plot.

None of the arrested men’s names or the charges against them were immediately disclosed. But two New Jersey newspapers, The Star-Ledger of Newark and The Record of Bergen County said the British suspect would be charged with material support of terrorism and weapons smuggling.