BELGRADE, Serbia (AP) — Serbian authorities say they are investigating reports of an alleged spying affair involving Russia, sparked by a video posted on social media.

Officials said Wednesday that the military intelligence agency has been instructed to look into claims that an alleged Russian military intelligence agent was filmed bribing a senior member of Serbia’s security service.

The video of the alleged bribery was posted on YouTube on Nov. 17. It apparently shows the Russian diplomat giving the Serbian agent a bag during a meeting in Belgrade. Later, the Serbian takes out an envelope with money from what seems like the same bag.

Serbia’s Defense Minister Aleksandar Vulin told the Tanjug news agency that the “situation is very serious.”

Serbia is seeking membership in the European Union but maintains close ties with Russia.