In a letter to Blazer, Lisle Austin, appointed interim president in place of the suspended Jack Warner, said the American was "terminated as general secretary of CONCACAF with immediate effect."
Austin said he considered Blazer had "grossly insulted and defamed" Caribbean associations by stating "that each member association was under investigation for bribery."
Blazer swiftly responded with a statement issued by CONCACAF's media office in New York that said the move was "unauthorised" and that the American remained in office.
The power struggle in CONCACAF, which governs football in North and Central America and the Caribbean, has underscored the crisis engulfing FIFA, whose delegates were set to re-elect incumbent president Sepp Blatter on Wednesday, despite global pressure to postpone the election.
Blazer was the whistle-blower who made allegations of corruption against Caribbean football federations, which led to the suspension of long-standing CONCACAF president Warner, a former ally.
Last week he produced a report to FIFA that alleged bribes had been paid by Qatari Mohamed Bin Hammam during a meeting with Caribbean federations in Port of Spain earlier this month.
Asian football chief Bin Hammam was at that time a candidate against incumbent FIFA president Sepp Blatter. He has since withdrawn and also been provisionally suspended by FIFA's Ethics Committee pending an inquiry.
Blazer is a member of FIFA's Executive Committee and is considered close to president Sepp Blatter.
Barbadian Austin, however, has been viewed as a close Caribbean ally of Trinidadian Warner and the letter was distributed by a media official in Port of Spain, capital of Trinidad and Tobago.
Earlier Tuesday, Blazer had reported Warner to FIFA, saying that he had breached the terms of his suspension which bars him from "football activities," resulting in a strong retaliation from the Trinidadian's camp.
The acting president Austin wrote that Blazer had "improperly appointed five non-elected members of CONCACAF to congress."
He also reiterated a complaint he made earlier that Blazer had no authority to hire Chicago-based lawyers Collins and Collins to collect information for the report which led to the suspension of Warner.
"The above conduct is inexcusable and a gross misconduct of duty and judgement. It is apparent that you are no longer fit to act as secretary general of CONCACAF and to represent its members," the letter concluded.
The subsequent CONCACAF statement said that Austin had no power to sack Blazer.
"Under the CONCACAF Statutes, jurisdiction over the General Secretary rests solely with the CONCACAF Executive Committee which has taken no action.
"Further a majority of the Executive Committee Members have advised Mr. Austin that he does not have the authority to take such action.
"Chuck Blazer continues as CONCACAF General Secretary and with the full authority of his office. The Confederation continues its normal o
