Wagner mercenary boss Yevgeny Prigozhin, who remains active despite leading a failed mutiny against the Russian army's top brass last month, has hailed Niger's military coup as good news and offered his fighters' services to bring order.

A voice message on Telegram app channels associated with Wagner that they said was Prigozhin did not claim involvement in the coup, but described it as a moment of long overdue liberation from Western colonisers and made what looked like a pitch for his fighters to help keep order.

"What happened in Niger is nothing other than the struggle of the people of Niger with their colonisers. With colonisers who are trying to foist their rules of life on them and their conditions and keep them in the state that Africa was in hundreds of years ago," said the message, posted on Thursday evening.

The speaker had the same distinctive intonation and turn of phrase in Russian as the Wagner boss although Reuters was not able to confirm with certainty that it was him.

"Today this is effectively gaining their independence. The rest will without doubt depend on the citizens of Niger and how effective governance will be, but the main thing is this: they have got rid of the colonisers," the message said.

Coup leaders declared General Abdourahamane Tiani as the new head of state on Friday days after saying they had ousted President Mohamed Bazoum in the seventh military takeover in West and Central Africa in less than three years.

The country, which is one of the poorest in the world but which also holds some of its biggest uranium deposits, declared full independence from former colonial ruler France in 1960.

The voice message was the latest sign that Prigozhin and his men remain active in Africa, where they still have security contracts in some countries like Central African Republic (CAR).

Prigozhin had told an African news outlet in an interview published online days earlier that Wagner was ready to increase its Africa presence and that a fresh batch of its fighters had arrived in CAR ahead of a constitutional referendum.

Wagner's role in Africa is a source of concern for Western governments, including France and the United States. Washington has accused the group of atrocities and imposed sanctions on it. Prigozhin says it works lawfully.

Hand shakes and praise for Putin

Prigozhin, 62, appears to continue to enjoy freedom of movement despite what the Kremlin said last month was a post-mutiny deal that would see him relocate to neighbouring Belarus where some of his men have already started training the army.

He was heard in a video released earlier this month telling his men in Belarus that they should gather their strength for a "new journey to Africa".

There have been various sightings of Prigozhin in Russia since the post-mutiny deal was clinched and the Kremlin said he had even attended a meeting with Putin, who had earlier called the abortive mutiny "a stab in the back".

The voice message's release coincided with the publication on Telegram of at least two photographs purporting to show Prigozhin meeting African attendees of a Russia-Africa summit in St Petersburg that concluded on Friday.

Reuters verified the location shown in one of the photographs as the Trezzini Palace hotel in St Petersburg, the home town of both Prigozhin and Putin. The lanyard worn by the official from CAR he is shown meeting in the same photograph matches those given to the summit's delegates.

Smiling and wearing blue jeans and a white polo shirt, Prigozhin looks relaxed in the photos as he poses to shake the hands of the delegates.

In his voice message, Prigozhin boasted of Wagner's alleged efficiency in helping African nations stabilise and develop.

In new comments to Cameroon-based Afrique Media broadcast on Friday evening, Prigozhin lauded the way the Africa summit had gone, praising Putin for forging what he called one-on-one working relationships with African leaders based on trust.

"Russia today offers both...economic relations and security exports, without which Africa today cannot exist," he said, according to a transcript posted on Wagner Telegram channels.

"The forum went well and we should see the results of it in the near future," he added, naming Mali, CAR and Niger as countries becoming "more and more independent".

Sergei Lavrov, Russia's foreign minister, said on Thursday that constitutional order in Niger should be restored.

Analysts said the Prigozhin appearances indicated that Wagner would continue to play a role in furthering the Kremlin's foreign policy agenda in Africa and were designed to send a signal of continuity to African partners after the tumult of the failed mercenary mutiny inside Russia.

"Yes, it's wild that Prigozhin is back in Russia, and apparently has been several times," Catrina Doxsee, an expert at the U.S. CSIS think tank, said on messaging platform X.

"But it's also in line with both Wagner's and Russia's goals to project normalcy and business as usual."