The military takeover in Gabon will merely lead to a continuation of rule by the Bongo clan which has been in power for 55 years, a source close to the deposed president has told the BBC.
"General Brice Oligui Nguema is a direct product of the Bongo clan," said the source, who wanted to remain anonymous for security reasons.
He warned those celebrating the coup not to expect too much to change.
The military vowed to put an end to the Bongo regime when they seized power.
They announced a military takeover shortly after President Ali Bongo had been declared the winner of a disputed election. He has been put under house arrest.
The military on Saturday said the country's borders would be reopened after they were closed following Wednesday's coup.
Our source's comments echo those of opposition leader Albert Ondo Ossa, who told the Associated Press that the coup was a "palace revolution", engineered by the Bongo family to retain their power.
The coalition backing Mr Ossa, Alternance 2023, which says it is the rightful winner of last Saturday's election, has urged the international community to push for a return to civilian rule.
"We were happy that Ali Bongo was overthrown but... we hope that the international community will stand up in favour of the republic and the democratic order in Gabon by asking the military to give back the power to the civilians," Mr Ossa's spokesperson, Alexandra Pangha, told the BBC.
She added that the plan for Gen Nguema to be sworn in as transitional president on Monday was "absurd".
The coup has been condemned by the UN, its neighbours and France - its former colonial power which had close ties to the Bongo family.
Gabon has been suspended from the African Union.
In a televised address on Friday evening, Gen Nguema said the military would move "quickly but surely" to restore civilian rule but did not give a timeline. He said they would avoid elections that "repeat the same mistakes" by keeping the same people in power.
However, our source said that the new strongman, the head of the elite Republican Guard, was "a direct product of the Bongo clan. He is the spiritual son of Omar Bongo and has always been closely tied to the presidential family", adding that some believe he is Ali Bongo's cousin.
Omar Bongo was in power for 41 years before his son Ali succeeded him following his death in 2009.
Ali Bongo's subsequent election victories have always been marred by opposition claims of widespread fraud.
Our source said that the coup caught everyone unawares, despite rumours floating around Gen Nguema.
"It completely took our team by surprise but for the past two years, there had been rumours alleging that if there was one man capable of disrupting the hierarchy, it would have to be him. He has always played a crucial role within the Bongo clan and has a natural but discrete authority."
It is said that just before Omar Bongo's death in 2009, Gen Nguema promised him he would look after his family. However, when Ali Bongo took over, the military man was sent away to serve as an attaché to the Gabonese embassies in Morocco and Senegal.
"Upon his return in 2019, Gen Nguema realised that the power circle had extended beyond the close members of the family and that the state control was slipping out of the grasp of the Bongo clan," explains our source. This was after Ali Bongo suffered a stroke which side-lined him for a year and prompted calls for him to step aside.
The coup has seen many people take to the streets of the Gabonese capital, Libreville, to celebrate but our source says this is mainly because "they wanted to be freed from the Bongo family name".
"But the reality is that the coup is very much a continuation of the same system just with a different name."
Shortly after the coup was announced, several allies of the ousted president were arrested, including his 31-year-old son Noureddin Bongo Valentin, who has been accused of high treason and corruption. National TV has shown images of him and other close Bongo allies in front of suitcases of cash it said had been seized from their homes. They have not commented on the allegations.
But our source says this is largely for show.
"He wants to send a strong message to the population by arresting the president's son.
"Everyone is celebrating now but we shouldn't forget that the transition leader ate at the Bongo family's table for decades. He has a lot of experience and was able to bring back hope, but the Gabonese people must remain alert".