Former president Sepp Blatter has said the decision to appoint secretary general Fatma Samoura as the 'Fifa General Delegate for Africa' is colonialist and flouts Fifa rules.
Last month, football's world governing body made the move in a bid to improve governance within the Confederation of African Football (Caf).
"This can be considered as a new aspect of colonialism," the Swiss told BBC Sport in a statement.
"Fifa's direct intervention to Caf and sending Mrs Samoura as a kind of 'supervisor' ignores the statutes of the federation.
"To recall, confederations are not members of Fifa. Only the national associations are."
Caf's Executive Committee (ExCo) is set to discuss Samoura's looming arrival when it meets in the Egyptian capital Cairo on Wednesday.
Despite previous claims by both Fifa and Caf that her appointment was 'unanimously' agreed by the latter's Executive Committee, there is still believed to be opposition by certain members of the 22-man board.
BBC Sport understands this opposition could be dropped if Samoura, who is set to start her six-month role - renewable if both Caf and Fifa agree to it - from 1 August, would answer to the ExCo rather than Fifa president Gianni Infantino and Caf president Ahmad, as previously mooted in a memo.
Should the latter scenario play out, Samoura and her team of advisors would sit above the ExCo in terms of any decision-making.
"It seems that only Tanzania's Leodegar Tenga realises the consequences of this action," added Blatter, who ran Fifa between 1998 and 2015.
"He warns the Caf Executive Committee not to agree to the appointment of Mrs Samoura."
Blatter was referencing Caf ExCo member Tenga since comments the latter made on a private WhatsApp group with Caf President Ahmad and fellow ExCo members were leaked to the media last month.
While there was an agreement 'in principle … to the cooperation between Fifa and Caf', Tenga wrote, 'we also agreed that Exco members would be given time to go through the proposed text and come up with the details.'
During the ongoing Africa Cup of Nations in Egypt, Caf secretary general Mouad Hajji outlined the advantages he believes Samoura will bring to the organisation.
"This is a great opportunity for Caf to benefit from her expertise," he told reporters.
"Madame Fatma will arrive with a group of experts, so this will only speed up the process of reform being led by President Ahmad and the ExCo with principles such as good governance, transparency and fairness.
"So we see all this in a very positive way."
