An agreement for a joint Russian-Serbian effort to fight cancer makes no reference to investigating the possible effects of NATO's bombing of Serbia two decades ago, despite Serbian media claims apparently based on statements by Russia's ambassador to Belgrade.
The contradiction surfaced after Serbia's state-run Institute of Oncology and Radiology inked a deal with its Russian counterpart in September on closer cooperation in research and other activities.
"We will do everything in our power for the best possible cooperation," Russian Ambassador Aleksandr Botsan-Kharchenko told attendees at the signing ceremony for the agreement, according to the Serbian daily Blic.
But he added: "Russia is also ready to investigate the consequences of the NATO bombing, which are more than obvious to cancer patients."
Some Serbian officials have argued that a link exists between the 1999 NATO bombings of Serbia within rump Yugoslavia and the incidence of malignant blood and other disorders among children exposed to bombed sites, despite medical evidence to the contrary.
Moscow staunchly opposed the alliance's attack on its closest Balkan ally and has since argued that NATO expansion into the former Eastern Bloc after the fall of communism represents a major threat to Russian interests.
NATO has added the former Yugoslav republics of Slovenia, Croatia, and, in 2017, Montenegro as new members. North Macedonia has also been approved as a member and is expected to officially join in 2020.
Botsan-Kharchenko reportedly went on to say in September: "Some will say that Russia wants to participate solely because of its negative attitude to NATO, but this is not true. Every doctor well knows: the cause of the disease must first be known and we will be working on it."
The bombing of rump Yugoslavia, code-named Operation Allied Force by NATO, began in March 1999 and was aimed at ending violence between ethnic Albanians and mostly ethnic Serbian forces during a two-year counterinsurgency war.
Belgrade's Institute of Oncology and Radiology told RFE/RL in response to a recent query that they hadn't conducted any research on the health consequences of the NATO bombings.
It added that it "is not actively involved in examining the consequences of the NATO bombing."
But institute officials declined to divulge the details of their agreement with the National Medical Research Radiology Center, which is under the auspices of the Russian Health Ministry.
RFE/RL's Balkan Service obtained a copy of the September agreement after an appeal to Serbia's commissioner for information of public importance and personal data protection.
The text commits its Russian and Serbian signatories to joint research and activities including seminars, student and professional exchanges, and other events.
It makes no mention of NATO's 1999 military campaign or related incidents.
It also obliges both sides to "keep confidential information about their activities" in connection with the agreement.
Serbian politicians and activists have launched multiple efforts -- some of them through state institutions -- to pursue suspicions on the possible health effects allegedly related to the NATO bombing.
They appear to rest on the use of ammunition containing depleted uranium during the 78-day aerial assault to force Belgrade to withdraw predominantly Serb-Yugoslav troops from Kosovo.
Serbian lawmaker Darko Laketic, who heads a parliamentary Commission for Researching Health Impacts of the NATO Bombing, said in March that a study commissioned by his group in tandem with the Batut Institute of Public Health had shown "unambiguously" that children born after 1999 were exposed to something left amid the rubble.
Other legislators said at the time that they had waited months for details of that study but "so far nothing."
But many medical experts say there is no link between depleted uranium and cancer.
Zoran Radovanovic, an epidemiologist and the chairman of the Serbian Medical Association's ethics committee, denied last year that there had been an uptick in cancer cases where the NATO bombings occurred, Balkan Insight reported.
He added that Serbians are often frightened about a cancer epidemic that does not exist.
NATO has said some 3,000 cruise missiles fell on targets across Kosovo and what is now Serbia during the campaign, including heavy bombardment of the capital, Belgrade.
Some of the munitions contained depleted uranium, a leftover product from the enrichment process for uranium 235. It is used in warheads because of its extreme hardness, which allows it to penetrate armored targets and fortified buildings.
But NATO has repeatedly claimed the depleted uranium shares no link to people suffering adverse health effects.
U.S. Ambassador to Serbia Kyle Scott told Balkan Insight last year that the World Health Organization and the United Nations had determined that depleted uranium does not pose a serious health risk.
Its radioactivity is far below that of its original form, but depleted uranium is still considered toxic and listed by the U.S. Environmental Protection Agency as a "radiation health hazard when inside the body."
Multiple Serbian news outlets linked the September agreement to the claims against NATO, citing the Russian ambassador.
"Russia will also assist Serbia in examining the consequences of the NATO bombing," because, according to the ambassador, "the consequences for human health are obvious," RTS said of Botsan-Kharchenko's appearance.
"Russia is seeking cooperation to investigate the consequences of NATO bombing at the state level," reported Belgrade-based Vecernje Novosti.
The Serbs' pullout from Kosovo in 1999 led to the establishment of a UN interim administration in Kosovo that paved the way to a declaration of Kosovar independence in 2008 that Belgrade and Moscow still don't recognize.
Moscow has long sought to leverage its close historical relationship with Belgrade to undermine Western institutions and oppose European integration efforts in the Balkans.
Those efforts have included diplomatic support for Serbia's opposition to Kosovo sovereignty and an abortive coup in Montenegro that involved Russian and Serbian intelligence officials in the run-up to Montenegro's NATO accession in 2018.
NATO cooperation with Russia was "suspended" in 2014 in response to that country's invasion of Ukraine, a nonmember that has since declared NATO membership a foreign-policy priority.