Federal officials tell ABC News the recruitment of the alleged White House spy began in July 2000. At that time, Joseph Estrada, then president of the Philippines, came to the White House for a state visit with President Clinton.
Officials say Estrada and his aides used offers of small amounts of money and appeals to ethnic loyalties to recruit Leandro Aragoncillo, the alleged spy, who was half a million dollars in debt.
"There's a lot of things this person could have access to, and the Philippines would want to know, 'What is the U.S. going to do?'" explained Jack Cloonan, a former FBI agent who is now a consultant for ABC News. "'What are they going to give us in terms of military support? What decisions are they going to make about us?'"
At the time of the recruitment, Aragoncillo was working as an intelligence analyst for Vice President Al Gore. He later told Philippine television that he was eager to stay in the White House and work for Vice President Dick Cheney.
"Because with the change of administration, everybody was asked if they wanted to stay and asked me, and I said, 'Well, I don't have to think twice. I will not think twice about staying here,'" he said.
Officials say even after Philippine President Estrada was forced out of office for corruption, Aragoncillo continued to feed him secret files in an apparent attempt to start a coup.
"The notion that classified documents would be transferred from the vice president's office into the hands of some political party challenging the regime of a foreign country is staggering," said Jane Harman, a Democratic congresswoman from California.
Officials say Aragoncillo passed several lie detector tests that are routinely given to individuals with top secret clearances. When he started to work as an FBI analyst at Fort Monmouth, N.J., last year, they say he was put on a fast-track hiring plan based on his connections at the White House.
"People who knew him and worked close to him said his office space was festooned with pictures of the White House, him with the president, him with the vice president," said Cloonan, the former FBI agent. "Believe me, that carries a lot of input and a lot of sway."
Meanwhile, today, a team of FBI counter-espionage agents continued their work inside the office of Vice President Dick Cheney. Some 35 past and present White House employees, who worked with Aragoncillo while he was at the White House, are being questioned. The hard drives of every computer that Aragoncillo used are being examined.
As for the findings of this investigation, officials tell ABC News that Aragoncillo, who was assigned to Mideast affairs, downloaded classified files involving a second country other than his native Philippines. They say they are also going through the files of Al Gore and Condoleezza Rice.
ABC News' Vic Walter, Avni Patel, and Rhonda Schwartz contributed to this report.