Officials said Friday they were looking for two people who are accused of plotting with a Korean-American and a British businessman to export deadly nerve gas from the United States.

Juwhan Yun, 48, of Short Hills was arrested Thursday at what he thought was to be a meeting with an arms supplier, who was actually a U.S. Customs Service undercover agent, said Richard Mercier, chief agent at Customs' Newark office.Yun was jailed pending a bail hearing Tuesday on charges of conspiring to illegally export sarin, a nerve gas. An arrest warrant issued for Charles Caplan, a London businessman who authorities said was trying to get the gas - $5 million worth in the form of 500 quarter-ton bombs - from Yun.

Caplan's extradition was being considered, U.S. prosecutors said.

Officials said they were seeking others in the case, Mercier said. The complaint filed in federal court said Caplan and Yun met in London on Monday about the gas deal with two other people, "as verified by a surveillance team."

Yun's arrest followed a seven-month investigation that involved the U.S. Department of Defense, the Army and Navy, and French and British customs officials. The case also included U.S. customs investigators in Paris, London, Seoul, Honolulu and Los Angeles, Mercier said.

The complaint detailed discussions between Yun, a naturalized U.S. citizen, and K.Y. Joo, identified as a close business associate of Yun and head of Kwang Jin Trading Co. in Seoul, South Korea.

Authorities said Yun and Joo, who was not named in the complaint, discussed at least three missile and military-radar equipment deals that apparently involved Iran as a destination.

Authorities said that at one point Iran was to be the recipient of the sarin. But that could not be verified, said First Assistant U.S. Attorney Michael P. Chertoff, who added there was no evidence government officials of Iran or any government were involved in the alleged gas deal.

The final destination may never be known, Mercier said.

"We don't have to know (it) to make a case," he said. Prosecutors must only prove that Caplan and Yun tried to circumvent licensing requirements by exporting restricted materials, he said. The charge carries a maximum five-year prison term and a $250,000 fine.

In November, the same month Customs said Caplan asked Yun to obtain the gas, Caplan finished a nine-month prison term in England for conspiring to export 50 gun silencers to Libya in 1985 through Domino Avionics.

Concern over the potential spread of chemical weapons has intensified recently. At a United Nations conference in Paris on Wednesday, more than 140 nations reaffirmed the 1925 Geneva Protocol banning the use of chemical arms.

Yun's arrest came the same day the West German government reversed itself and said it suspected German companies helped build a Libyan plant the United States believes is a chemical weapons factory. Libya says the plant will produce medicine.