Kirk Fordham gave crucial testimony behind closed doors as investigators sought to learn who is telling the truth. Fordham said he gave the information to Hastert chief of staff Scott Palmer in 2002 or 2003, but Palmer has disputed Fordham's account. Hastert's office said his staff was first told about Foley last fall.
Before Fordham appeared, a Republican member of the House page board, which oversees the program for teenagers, said she was never told about Foley.
Rep. Shelley Moore Capito, R-W.Va., said after her questioning, "I'm a member of the page board who was not informed of the e-mail messages that were sent. I want the investigation to go forth quickly and reach a conclusion."
Capito's Democratic opponent had earlier accused her of failing to protect the high schoolers in the page program.
Keeping Capito out of the loop would raise questions about whether other Republicans tried to tell as few people as possible about Foley as part of a cover up. She is one of three members of Congress who serve on the page board. Rep. Dale Kildee of Michigan, the lone Democrat, also said he was not told about Foley.
Capito's testimony preceded that of Fordham, who was ready to directly question the truthfulness of Hastert's top aide.
Fordham said he could demonstrate that he warned Palmer about Foley's approaches to male pages in 2002 or 2003. Palmer has challenged Fordham's description of events.
Capito said she knew nothing about the allegations until Sept. 29, when Foley's conduct became a major Capitol Hill scandal.
"It disturbs me greatly. I am very upset about it and I think it is disgusting, quite frankly," Capito said in a West Virginia debate Wednesday after her opponent accused her of shirking her responsibility. She has called for more members on the page board, more training for those members, and peer counseling for the pages.
According to a timeline released by Hastert, the speaker's office was informed about an overly friendly e-mail that Foley sent in the fall of 2005. Subsequently, the clerk of the House and Rep. John Shimkus, R-Ill., head of the page board, met with Foley, who assures them he was only acting as a mentor to the boy. Shimkus ordered Foley to cease contact with the boy, apparently without notifying Kildee or Capito.
Shimkus will testify Friday.
At a recent news conference, the speaker said that Shimkus was following the wishes of the parents of the former page by not telling other page board members about it.
"I think Congressman Shimkus acted in an expedited manner to find out what happened, again with what the framework of what the family concern was," Hastert said.
Shimkus also said he did not inform the other board members because he was following the wishes of the boy's parents.
Meanwhile, House Majority Leader John Boehner has been invited by the ethics panel to testify, but no date has been set. Boehner has said he informed Hastert about Foley and was told the matter was being handled. Hastert has said he doesn't recall the conversation.
Hastert's aides said they first learned of an overly friendly Foley e-mail to a former page in the fall of 2005 — and never knew about sexually explicit messages to others until late last month when they became public.
The FBI also is investigating, trying to determine whether any crimes were committed by Foley.
On Wednesday, agents interviewed former page Jordan Edmund, now 21.
CBS News has learned that Edmund told the FBI he had limited contact with Foley as a page in 2001 and 2002, but that after Edmund left the page program Foley began e-mailing him.
They met in person twice, including for dinner in San Diego in 2002. They went to Foley's hotel room but Edmund told agents he left after about 20 minutes and nothing untoward happened, CBS News correspondent Sharyl Attkisson reports.
While the ethics committee will try to learn who's telling the truth, the court of public opinion appeared to be moving against the Republicans, who hold majorities in the House and Senate.
Polls show most Americans say the House Republican leadership worried more about politics than the safety of teenage pages. However, most also say Democrats would not have handled the situation better.
Several polls also show a split on whether Hastert, R-Ill., should step down, with just under half of those surveyed saying he should. More than half in several polls said Hastert tried to cover up what he knew about Foley.
Next week, the ethics panel also is to hear from Rep. Rodney Alexander, R-La., whose testimony also is poised to raise questions about how GOP leaders handled the Foley problem. A former page he sponsored from Louisiana received friendly e-mails from Foley that were not sexually explicit but raised questions about Foley's motives.
The former page contacted Alexander's office about Foley in fall 2005. Foley, R-Fla., had asked the boy's age — then 16 — and his birthday. Foley also requested a photo.
There is no dispute that Alexander's chief of staff, who also will be questioned, called Hastert's office. This, according to a report by Hastert, was the initial notification that something was wrong.
Last spring, Alexander mentioned the Foley situation to Boehner, R-Ohio. Alexander said Boehner referred him to Rep. Tom Reynolds, R-N.Y., chairman of the House Republican campaign organization.
Both Boehner and Reynolds said they spoke with Hastert, who says he cannot recall those conversations and raised questions about whether they occurred.
Boehner initially quoted Hastert as telling him the Louisiana page's complaint "had been taken care of."
Foley resigned Sept. 29 after his sexually explicit instant messages to former pages became public.