Russia on Tuesday protested to its ex-Soviet ally Belarus over the "unacceptable" arrest of the chief executive of the leading Russian potash producer, who was detained in Minsk just hours after he met the country's premier.
Uralkali chief executive Vladislav Baumgertner was arrested at Minsk airport on Monday after visiting Belarus on the personal invitation of Prime Minister Mikhail Myasnikovich.
He was detained three weeks after Uralkali severed links with its Belarussian partner Belaruskali, triggering a crash in the share prices of global manufacturers of the fertiliser.
In a rare diplomatic row between Minsk and Moscow, Russia summoned the Belarussian ambassador for a meeting at the Russian foreign ministry.
Russian Deputy Foreign Minister Grigory Karasin told Belarus' ambassador Igor Petrishenko in Moscow that "the arrest of the businessman... is unacceptable," the ministry said in a statement.
"The arrest and information campaign surrounding it does not reflect the allied nature of our relations and could affect the scheduling of Russian-Belarussian contacts at a political level," it added, demanding Baumgertner's release.
The spokesman of the Belarus foreign ministry, Andrei Savinykh, hit back by saying the arrest should be "examined in the spirit of the law and not based on emotion and linkages to politics", a statement said.
Russia's ambassador to Belarus Alexander Surikov subsequently had a meeting at the Belarussian prosecutors' office in Minsk to discuss Baumgertner's arrest, Belarus state media said.
Belarussian investigators claim to have uncovered an illegal scheme by Baumgertner and other Uralkali managers to enrich themselves at a cost of $100 million to Belarus.
Baumgertner can now be held in custody for two months, although that can be extended, the spokesman of the Belarussian Investigative Committee, Pavel Traulko, said Tuesday.
"The accused is currently being interrogated," he told AFP in Minsk.
Belarussian state-controlled media have played up the arrest, with daily newspaper Belarus Segodnya (Belarus Today), which is run by the presidential administration, saying Uralkali's behaviour was similar to the "bandit capitalism" of the 1990s.
State television in a report entitled "Crime of the year" showed Baumgertner after his arrest being searched by security officers with his arms and legs spread apart and face against the wall.
Four other managers at Uralkali have also been put on a wanted list by Belarussian authorities, but they are currently all believed to be in Moscow.
The Belarussian Investigative Committee also said that it is looking into Suleiman Kerimov, the billionaire owner of Russia premier league team Anzhi Makhachkala and a major Uralkali shareholder, for unlawful activities.
The arrest of Baumgertner shocked observers, given the regime of strongman Belarus President Alexander Lukashenko is hugely dependent on cheap energy imports from Russia and Russian credits to keep its economy afloat.
A source close to Uralkali told Russia's Kommersant daily that the approval for such an arrest could only have come from Lukashenko, who has been in power for almost two decades.
The source added that Baumgertner's meeting with Myasnikovich had been "far from constructive".
"Of course (Mikhail) Myasnikovich knew about it (the impending arrest). The meeting with him was used as bait," the source told Kommersant.
The mercurial Lukashenko has needled Russia on occasion with his sometimes maverick behaviour but observers believe the Kremlin prefers him to a pro-West figure who could steer Minsk toward the European Union.
Lukashenko faced protests after his controversial re-election in 2010 and a severe economic crisis afterwards but largely remains unchallenged at the helm of Belarus.
Described as running Europe's last dictatorship by the United States and again treated as a pariah by the EU after the 2010 polls, Lukashenko is greatly bolstered by Russian support.
Uralkali accounts for about 20 percent of global potash production and the severing of its joint venture with Belaruskali was seen as marking the end of a cartel that has supported global potash prices.