Lawyers in Guinea are accusing the government of publishing a different constitution to the one that was approved in the 22 March referendum.
The Guinea Bar Association cited extensive modifications to the original draft. It said many paragraphs had been substantially changed or replaced.
Opposition leader Cellou Dalein Diallo is quoted by RFI as saying that the move was in contempt of the law.
President Alpha Condé’s party have said no changes were made to the constitution.
The country’s minister for justice has called a press conference following the allegations.
One of the changes approved would allow Mr Condé to seek a third term in office.