Nemanja Ristic, who is wanted in Montenegro for conspiracy to kill Djukanovic in an alleged foreign-organized coup attempt in October, posted the image on his Instagram account on December 13, according to RFE/RL.
The photo shows Ristic standing just steps away from Lavrov at a ceremony at the Grave Of Liberators cemetery in the Serbian capital on December 12.
Read alsoMontenegro says foiled Russian-backed plan to kill PM DjukanovicThe three women with whom Lavrov is posing in the photograph are all members of the right-wing nationalist Serbian group Zavetnici (Patrons), which participated in a wreath-laying ceremony to honor the fallen Russian soldiers. One of the members of the group, Milica Djurdjevic, told RFE/RL’s Balkan Service reporter on the scene that Ristic is not a member of the group.
The presence of Ristic so near to Russia's top diplomat raises multiple questions, including how he entered the premises, which were tightly secured for Lavrov's visit.
It also raises questions about Belgrade's cooperation with a Montenegrin investigation into an alleged plot that involves two Russian citizens, more than 20 Serbian and Montenegrin citizens, and unidentified members of Montenegro's Russia-leaning main opposition party.
The prosecutor's office first announced it had foiled the alleged coup attempt on October 15, just hours before polls opened.
Read alsoMontenegro puts on int’l wanted list two Russians suspected of coup attemptMoscow has said it had no official role in the alleged coup attempt.
"We, obviously, categorically deny the possibility of official involvement in arranging any illegal actions," Kremlin spokesman Dmitry Peskov told reporters on November 7.