Addressing growing reports over the last few days that Chechen armed men joined the separatists fighting Ukrainian forces in the east of the country, the Moscow-backed president of Chechnya Ramzan Kadyrov said on Tuesday that the reports were untrue — or, at least, that he didn’t send anyone there.

The leader denied that scores of Chechens from Chechnya — as opposed to members of its large diaspora — did indeed end up in Ukraine from the Caucasus republic — which is part of the Russian federation, despite a long history of separatist aspirations of its own.

As a member of the Russian federation, Kadyrov said, Chechnya has no autonomous armed forces.

"Ukrainian sources have been circulating reports that some Chechen units from Russia have invaded Donetsk,” Kadyrov said in an Instagram statement. “I officially declare that this is not true."

But widespread reports — including several videos — have documented the presence of the Vostok Battalion, a unit of Russia's military intelligence (GRU) based in Chechnya, in Donetsk, where they reportedly participated in a deadly battle at the city's airport on May 26, which left at least 50 separatists dead.

'We know how it looks when people are humiliated, so we have come to help.'

The Chechen Vostok Battalion was technically disbanded in 2008, after its participation in the Russo-Georgian War over Abkhazia and South Ossetia.

"I doubt Kadyrov sent them directly, not least because the original Vostok Battalion was controlled by the Yamadaevs, his bitter rivals, and it was disbanded precisely because Kadyrov didn't want to see them with their own unit," Mark Galeotti, an expert on Russian security affairs, told VICE News. "But he presumably must have OKed at least the temporary detachment of those of the unit who had taken jobs in the Chechen security apparatus."

"They may be there as adventurers and mercenaries, although clearly with the encouragement if not actual mobilization by the Russians — probably the GRU, military intelligence," he added.

The video below, uploaded to Russian social media site VKontakte today, shows an armored personnel carrier (APC) driving through Donetsk, carrying a Russian flag and a "Vostok Battalion" inscription. The inscription has also appeared elsewhere in the city.

Video by Tonya Mergaut via VKontakte

Vostok Battalion has branded their name on a fire station next to the — Isaac Webb (@isaacdwebb)May 28, 2014

Before being disbanded, the Vostok Battalion was run by commander Sulim Yamadaev — a rival of Kadyrov who was killed in Dubai in 2009.

"Vostok has not existed for a few years now. Moreover, it’s associated with Kadyrov’s long-time foes," Ekaterina Sokirianskaia, North Caucasus project director at the International Crisis Group, told VICE News. "Reviving Vostok as a brand could be another trick to divert attention from the incumbent Chechen authorities."

If Kadyrov is behind the rebranding, he's not admitting it publicly.

"There are three million Chechens and two-thirds of them live outside the Chechen Republic, including in the West,” he said. “We cannot know and are not supposed to know which of them goes where."

But in an apparent contradiction, he also said that if any Chechens from Chechnya are there, they went there on their own.

Kadyrov’s words were directly contradicted by Chechen fighters in Ukraine.

Several Vostok Battalion troops speaking Chechen today. One woman asks one of them, — Christopher Miller (@ChristopherJM)May 25, 2014

VICE News met a few of them earlier this week.

"Our president [Ramzan Kadyrov] gave the order. They called us and we came,” 33-year-old Zelimhan told reporters. The bearded fighter, a member of a unit known as the “Wild Division,” said he arrived a week ago with 34 Chechen men who volunteered to come and support their “brothers” in the People’s Republic of Donetsk.

“We know how it looks when people are humiliated, so we have come to help,” 30-year-old Magomed, another member of the Chechen unit, said.

Despite the official denials there is little doubt that Chechens have been flocking to eastern Ukraine to help separatists there in their fight against the Kiev authorities. They are not the only ones — as pro-Russia militias from Crimea, and reportedly other parts of Russia, have also joined the fight.

'Our law enforcement today in eastern region of Ukraine are facing well prepared and armed Russian mercenaries.'

Ukraine's foreign ministry said on Tuesday that the presence of foreign fighters amounted to “undisguised aggression” from Russia and “the export of Russian terrorism to our country”.

“There are grounds to affirm that Russian terrorists funneled on to the territory of Ukraine are being organized and financed through the direct control of the Kremlin and Russian special forces,” the ministry said, according to the Financial Times. “Our law enforcement today in eastern region of Ukraine are facing well prepared and armed Russian mercenaries ready to rob, intimidate, torture and kill Ukrainian citizens.”

Ukrainian and Western authorities have consistently accused Moscow of interfering in the region — accusations that Russian officials have just as consistently denied.

'Kadyrov can publicly deny the involvement of his men, just as Putin first denied the involvement of Russian troops in Crimea, but people in the Kremlin will know.'

But the reports of Chechen fighters in Ukraine might be a bit overblown, some suggested.

"The Chechen presence might be somewhat exaggerated to incite fear, as pro-Moscow Chechen groups have a notorious reputation for their disregard of law and grave human rights violations," Sokirianskaia said. "At the same time I cannot exclude the possibility that Chechen 'volunteers' have actually been sent by the Chechen government in some numbers, to do certain types of work that legal official Russian security agencies can’t do for obvious reasons."

"Sending such volunteers is in the interest of the incumbent Chechen authorities as it gives them a chance to once again prove their loyalty to Vladimir Putin and emphasize their Russian patriotism," she added. "Kadyrov can publicly deny the involvement of his men, just as Putin first denied the involvement of Russian troops in Crimea, but people in the Kremlin will know and appreciate the contribution."

APCs like the Vostok Battalion one were also seen in Donetsk as early as May 20 and in following days.

The videos below, taken on May 25 — election day in Ukraine — show men in Vostok Batallion fatigues, and reportedly speaking Chechen.

Chechen rebels fought and lost two brutal wars for independence from Russia — making some Chechen fighters' siding with pro-Russia separatists in Ukraine an interesting development. But Kadyrov is loyal to Putin, as are presumably any militias he may control. The 37-year-old former rebel has been credited with bringing stability to the conflict-ridden republic — a feat critics said he achieved through widespread human rights violations.

Chechnya has also been home to a separatist insurgency that has continued past the end of the wars, and expanded into neighboring republics in the North Caucasus region, and especially Dagestan, Ingushetia, and Kabardino-Balkaria.

Not all Chechen separatists joined the insurgency, however, and some are now finding themselves on a decidedly pro-Russia side of the Ukrainian conflict.

"The Vostok Battalion seems drawn largely from the former rebel fighters who defected to the government when the Chechen rebellions became both unsinkable and also increasingly dominated by jihadists," Galeotti said.

After Russia annexed Crimea, last March, deeply alienating the peninsula's Muslim Tatar minority, there were predictions that Crimean Tatars would join the North Caucasus' separatist Caucasus Emirate, which includes many Chechen jihadis.

At that time, jihadi forums buzzed with the slogan "Nafir for Ukraine" — which suggested the possibility of Chechens — and others — fighting in Ukraine, though not quite on the side they are currently fighting with.