"There is no confirmation of a possible exchange amidst controversial reports," union secretary Timur Shafir told ITAR-TASS.
Earlier reports have quoted Stenin's colleagues as suggesting he might be exchanged for what was described as a well-known individual. Journalists' union chairman Vsevolod Bogdanov, citing unnamed sources, told Russian News Service that Kiev, Ukraine's capital, "had suggested negotiations."
Reports have said Stenin may have been detained by Ukrainian law-enforcement bodies. On August 16, Ukrainian police put him on the missing persons list.
Union secretary Shafir, heading the body's international department, said it would continue to handle the issue together with international bodies in the joint campaign for Stenin's early release.