Kirk Fordham’s message to the office of the Republic leader in the House of Representatives is the earliest known alert to Republican leaders.
He says that when he was told about Mr Foley’s inappropriate behaviour toward pages, he had "more than one conversation with senior staff at the highest level of the House of Representatives asking them to intervene."
The conversations took place long before the email scandal broke, Mr Fordham said, and at least a year earlier than members of the House Republican leadership have acknowledged.
Mr Fordham resigned on Wednesday as chief of staff to Representative Thomas Reynolds, a House Republican leader.
He spoke after American television station, ABC quoted unidentified Republican sources as insinuating that he had intervened on behalf of Foley, his former boss, to prevent an inquiry into Foley's conduct.
"At no point ever did I ask anyone to block any inquiries into Foley's actions or behaviour," Mr Fordham said.
Adding that he will fully disclose to the FBI and the House ethics committee "any and all meetings and phone calls" regarding Mr Foley's behaviour.
Explanation rejected
Many leading Republicans have publicly rejected Mr Foley's explanation that his lurid emails and text messages to the pages, at least one aged only 16, were in some way related to sexual abuse he claims to have suffered when he was a teenager.
"He has defamed himself, he has defamed this Congress," said two prominent Republicans, Representative Mike Pence and Joe Pitts in a joint statement.
"Worse than any of these, he has violated the trust and innocence of a number of young people."
Senator Dianne Feinstein, a senior member of the opposition Democrats, has called for heads to roll.
"It is clear that there was knowledge of improper, immoral, and possibly criminal behavior, and the leadership did nothing about it. That leadership should go."