A daughter of deposed Nigerien president Mohamed Bazoum on Friday accused his predecessor of being the "mastermind" behind the military coup that toppled her father nine months ago.

Bazoum and his wife have been under arrest in the presidential palace in Niamey since army officers seized power on July 26.

He had been elected two years earlier, succeeding president Mahamadou Issoufou, in Niger's first-ever peaceful transition since independence.

"The hardest thing to accept was to discover that Mahamadou Issoufou was the mastermind who orchestrated everything out of egocentrism and to protect his personal interests," Bazoum's daughter Hinda Bazoum wrote in an article for Nigerien newspaper L'Autre Republicain.

"The coup would enable him to return to power after a short military transition during which a new constitution would be adopted," she claimed.

Junta chief General Abdourahamane Tiani is a staunch ally and reputed confidant of Issoufou.

Bazoum had been interior minister and right-hand man to Issoufou, who voluntarily stepped down after two terms.

"It is very painful for us to know that their oppressors are people we knew and with whom we had cordial relations," his daughter wrote.

"He, who was close to our parents for 33 years and saw us grow up... he, my father's friend and brother, is betraying him in the most cowardly and cruel way."

In July, Issoufou posted on social media that he intended to negotiate with the junta to restore Bazoum to the presidency.

According to Hinda Bazoum, Issoufou's "latest trick" was to petition the new state court to lift Bazoum's immunity and then have him sentenced by the military court, so that Issoufou would be the "only candidate" of their party in the event of presidential elections at the end of a transition period.

For her and her sisters, she said "our lives no longer have any meaning and ended on July 26".

"In fact, my sisters and I are upset and bruised, because the last time we spoke to our parents was on October 18, 2023."

She urged "national and international opinion to mobilise in order to put an end to this cruel ordeal for our family".

Niger is also struggling against two jihadist insurgencies -- one in the southwest, which swept in from Mali in 2015, and the other in the southeast, involving jihadists from northeastern Nigeria.