When Alpha Condé started hinting he wanted to change Guinea’s constitution to allow himself a third term as president, he found a fervent supporter in an unexpected quarter.

Describing Condé as “legendary”, the Russian ambassador to Guinea backed a change of the constitution to allow the octogenarian president to “reinvigorate” the country.

“Do you know many countries in Africa that do better? Do you know many presidents in Africa who do better?” Alexander Bregadze asked in a new year’s broadcast on state television. “It’s constitutions that adapt to reality, not realities that adapt to constitutions.”

The opposition, civil society and the Guinean press were quick to criticise the ambassador’s “populist and demagogic” meddling. “He’s campaigning, supporting the president, encouraging the diplomatic corps to support a third term. It’s anti-constitutional,” said Alpha Baldé, of the opposition Guinean Democratic Forces Union.

In May, leaving his post as ambassador, Bregadze took a job at the Russian aluminium firm Rusal. He now heads up Rusal’s key unit in Guinea, home to its biggest mining interests.

Alpha Condé and Vladimir Putin in Moscow in 2017. Photograph: AFP Contributor/AFP/Getty Images

Russia has been trying to rekindle Soviet-era relationships with governments across the African continent and build new ties. Arms and military advisers have been supplied to countries such as the Central African Republic. Pro-Kremlin, regime-friendly “observers” have been sent to fraught elections in Zimbabwe and the DRC, producing positive takes on elections marred by rigging and violence.

While it cannot compete with China’s economic might on the African continent, Russia is carving out its own role, focusing on relationships such as that with Guinea.

Formerly a self-described Marxist socialist revolutionary state and the first French colony to become independent in Africa, Guinea was ideologically very important for the Soviet Union.

Several activists claim Bregadze’s comments are linked to Russia’s economic interests in Guinea. That is the view of Amadou Bah, the executive director of Action Mines, a charity that monitors Guinea’s mining industry. He said Russian companies “derive enormous economic benefits for a Russian oligarchy that has considerable weight in the political and economic affairs of this country”.

For some years Russia’s interests in Guinea have mostly been in mining. Guinea gets around a third of its revenues from the extractive sector.

Rusal owns the Kindia Bauxite Company (CBK), which accounts for a third of Rusal’s bauxite output, as well as the Dian-Dian Bauxite Company and the Friguia complex, which mines bauxite and refines it into alumina. Nordgold, another Russian company, owns a goldmine in northern Lefa, into which it is pumping ever-greater sums.

The Nordgold mine in Lefa. Photograph: Nordgold

Early in Condé’s first term, Guinea adopted a new mining code that it seemed would change the way mining companies operated, requiring them to pay more tax and protect the environment and the interests of communities around their mines.

It was quickly revised when companies froze billions of dollars of investments in the country, and the government showed a willingness to relax the rules for favoured partners. Companies such as Rusal whose agreements were due to expire had them extended under the old terms for another 25 years. CBK’s, for instance, was extended to 2050. According to a report by the extractive industry watchdog Publish What You Pay, it is exempt from paying taxes on land and salaries.

“The Russians have a special status in Guinea. That explains the advantages given to their mining companies,” said Bah, alleging that he knew of a secret agreement between the two countries.

There is a difference between the Russian government and transnational companies, said Alexandra Arkhangelskaya of the Russian Academy of Sciences’ Institute for African Studies, and the comment made by the ambassador “probably reflects the Russian attitude and the posture on global affairs,” not Rusal’s interests.

Alexis Arieff, an Africa policy analyst at the US Congressional Research Service, said the spurs for Russian interest in African countries could be drawn as a Venn diagram. “Does the country have useful mineral resources, is the country ripe for challenging the influence of key western actors, is the country a market for Russian arms?” she said. “Those seem to be key circles that when they overlap may lead to greater Russian interest. The other circle that is certainly present in Guinea is: is there a historic Russian diplomatic and military relationship?”

Securing valuable votes on the UN security council and worrying western nations are two reasons for the Russian push in Africa, analysts say. Russia has succeeded in the latter: the US general responsible for military operations in Africa said in February that in CAR “elected leaders mortgage mineral rights for a fraction of their worth to secure Russian weapons”.

Russia is not the only foreign power with interests in Guinea, which firmly cut ties with its former colonial master, France, after independence. China signed a $20bn infrastructure-for-minerals deal in 2017, under which three Chinese companies get bauxite concessions. The Israeli billionaire Beny Steinmetz’s company BSG Resources recently dropped out of a massive iron ore project after a long dispute.

Conakry, the capital of Guinea. Photograph: Friedrich Stark/Alamy Stock Photo

A Rusal spokesman said there was no conflict of interest regarding Bregadze’s appointment and no “secret strategic accords” between Rusal and Guinea. Responding to a follow-up question clarifying that the alleged secret agreement was between Guinea and Russia, the spokesman said: “The clarification does not change our response. There are no such ‘secret strategic accords’ concerning Rusal.”

The Guinean foreign ministry and the Russian embassy in Conakry were approached for comment.

Rusal will want to avoid a repeat of an incident in 2009 when its representative in Guinea was interrogated and berated on the then president’s bizarre late-night television show over the neglect of the company’s factory.

Condé’s opponents have launched a campaign to prevent him from changing the constitution, and Russia’s backing does not carry the weight that the USSR’s did, according to Bah. “Russia has nothing to teach us in terms of democracy or the functioning of the state,” he said. “It’s up to us to run and develop our country.”

Additional reporting by Fatoumata Kanté in Conakry

• This article was amended on 27 August 2019 because Rusal’s Friguia complex mines bauxite and refines it into alumina, not aluminium as an earlier version said.