fighting for Libyan warlord Khalifa Haftar are central to the , according to a recent investigation into the paramilitary organisation by the BBC.
A "shopping list" of and a tablet which belonged to a were vital to the UK public broadcaster's report, released on Tuesday.
Specialists suggested there is no possible source for such items except the Russian military's stock.
Moscow rejects all suggestions it has ties with Wagner.
Wagner initially became known through its support for Russia-aligned rebels in Ukraine, though it has spread it operations much further, including to Syria and Sudan.
Wagner mercenaries began their involvement in Libya over two years ago, when they stepped in on the side of Libyan warlord Khalifa Haftar in his assault against Libya's internationally recognised government in Tripoli.
The war in the North African nation halted following a truce agreed last October.
The BBC also spoke to two ex-Wagner mercenaries, one of whom acknowledged that those taken captive by the paramilitary group are liable to be killed.
"No-one wants an extra mouth to feed," they said.
The tablet the BBC gained access to was formerly in the possession of an unidentified mercenary.
The Samsung device fell out of this combatant's hands as Wagner pulled out of the capital's southern surroundings last year.
Its contents suggest Wagner played a part in laying mines and "booby-trapping" non-combatant locations.
The device has Russian-language maps of the battlefront, video from drones, and even codenames belonging to mercenaries part of the organisation.
The BBC suggested it had been able to determine who "at least one" of these mercenaries is.
The so-called "shopping list" came to the BBC as part of a file a Libyan intelligence insider provided to the broadcaster.
This was likely found in a Wagner site and bears 19 January last year's date.
It suggests where the money and support for the mercenaries' activities could be coming from, and details items required for "competition of military objectives".
Among these are four tanks and high-brow radar technology.
One expert said certain items on the list could only have been acquired from Russia's armed forces.
A second suggested it implicated Dmitry Utkin.
It is thought Utkin, who previously served in the Russian Federation's intelligence services, established the Wagner mercenary group, calling it after his ex-callsign.
The BBC attempted to reach out to Utkin, though there was no response by the time of publication.
Referring to a separate file as well as the list of military items, the second specialist suggested that two references implicated the businessman Yevgeny Prigozhin.
These included mention of Evro Polis, a firm the United States Treasury levied sanctions against in 2018, saying it "protect[ed]" oil fields located in Syria which the Putin associate "owned or controlled".
According to the US Treasury, the organisation is a "Russian company".
Prigozhin, whose ties with the Russian president are strong, has consistently rejected all suggestions he is connected to Wagner or Evro Polis.
A representative for the Russian businessman again said he has no relationship with Wagner or Evro Polis.
"I am sure that is an absolute lie", Prigozhin said in relation to the idea that Russians in Libya had perpetrated human rights abuses.