Justice Minister Seraphim Moundounga has resigned in protest over the disputed presidential election in Gabon.
He is reported to have warned the incumbent, Ali Bongon that he could cancel the results of the election if they did not “tally with reality”.
Mr Bongo was declared the winner by a narrow margin last Wednesday, but the opposition say the poll was fraudulent.
His rival Jean Ping has called for a general strike and says dozens of his supporters have been killed.
Mr Moundounga is the first senior government minister to resign over the election result.
The Gabonese authorities say three people have died and 105 have been injured following violent clashes and mass arrests that have taken place since the election result was announced.
There have been more than 800 arrests and France says several people with dual French-Gabonese citizenship remain unaccounted for.
The official election result gave Mr Bongo a second seven-year term with 49.8% of the vote to Mr Ping’s 48.2% a margin of 5,594 votes.
Mr Ping won in six out of nine provinces but disputes the result in Mr Bongo’s home province of Haut-Ogooue, where turnout was 99.93% and 95% of votes were for the president.
According to Gabon’s interior ministry, turnout in the other provinces was between 45% and 71%.
The former African Union diplomat has called for a recount, which has so far been resisted by the government.