As the inquiry widened into the bombing on 26 February, investigators said it was looking more and more like an international attack, with links to Europe and the Middle East.
The FBI in New Jersey disclosed the existence of the joint bank account on Wednesday when it announced the arrest of Nidal Ayyad, a chemical engineer believed to be the person who assembled the bomb.
One source said dollars 8,000 ( pounds 5,500) was transferred into the account, including funds received from Europe just before the bombing, and investigators were exploring other possible accounts. No more details were forthcoming, but the evidence is the latest to indicate that the attack was more than a locally orchestrated plot.
Mr Ayyad was born in Kuwait. His parents are Palestinian. The federal complaint against him alleges that he had close ties to Mohammed Salameh, a West Bank Palestinian from Jordan who was arrested on 4 March. Both men are charged with aiding and abetting in the attack.
Among the links disclosed by the FBI were numerous phone calls made from a storage locker, where bomb chemicals were stashed, to Mr Ayyad's office. He is employed at Allied-Signal, a diversified manufacturer and chemicals group.
The two rented a car together in mid-February and drove it to a truck rental agency where Mr Salameh rented a van which the authorities say took the explosives to the centre.
The FBI's New Jersey director, James Esposito, said on Wednesday that Mr Salameh and Mr Ayyad appeared to be key figures in the attack. But he did not describe either as the mastermind behind the bombing.
A third person, Egyptian-born Ibrahim Elgabrowny, was also being held after assaulting two federal agents who were searching his flat. Prosecutors said at Mr Elgabrowny's court hearing that he was considered a suspect in the bombing, but they have not disclosed what link he might have had.
Mr Salameh and Mr Elgabrowny have links with El Sayyid Nossair, who is serving a prison term for assault and weapons possession in connection with the killing of Rabbi Meir Kahane in November 1990. The three men are fundamentalist Muslims who worship at mosques where Sheikh Omar Abdel-Rahman regularly preaches. Mr Abdel-Rahman is spiritual leader of an Egyptian fundamentalist group seeking the overthrow of the Mubarak government.
He has condemned the bombing and says he was not involved in any way. But his fiery sermons have called for violence on behalf of Islam. Authorities said this week that his group was a focus of the investigation.