By Elizaveta Gladun, Małgorzata Wojtunik, Luiza Ilie and Krisztina Fenyo

BUCHAREST (Reuters) - Romania faces a wave of online disinformation ahead of a presidential election runoff this month in which the hard-right looks poised for victory, election observers and analysts say.

Hard-right eurosceptic George Simion secured 41% of the vote in Sunday's first round, just five months after another far-right candidate, Calin Georgescu, unexpectedly came first in a ballot that was later annulled due to suspicions of Russian meddling.

Simion will now face Bucharest mayor, Nicusor Dan, an independent centrist, in a May 18 run-off in the European Union and NATO member state.

Moscow has denied that it was behind a surge in activity on TikTok and other social media platforms late last year favourable to Georgescu. On Monday the Kremlin said he had been arbitrarily thrown out of the race.

The Romanian authorities and TikTok both say they have put measures in place to counter disinformation online. However, the European Commission has opened formal proceedings against TikTok over its suspected failure to limit interference in last November's vote.

Sorin Ionita, a political analyst, noted the prevalence of inauthentic social media networks backing political parties, which is reminiscent of the situation before the canceled election when TikTok accounts surged.

"These are bots definitely," he said of non-political dormant accounts that appear to belong to a lady with a nail salon, or someone who comments on football or cars, and which suddenly begin to post political content and get thousands of views.

OpenMinds, a tech company focused on countering authoritarian influence, said its investigation found that 24% of Romanian-language Telegram channels are spreading what it called Kremlin-backed disinformation.

The report said one in four messages on these channels promotes material from Russian state media and other pro-Kremlin sources.

Since early 2022, 48 Telegram channels have posted over 4,000 entries aimed at undermining trust in democratic institutions and fueling conspiracy theories, including claims of a "coup" following the cancellation of the 2024 election, OpenMinds told Reuters.

Telegram did not reply immediately to Reuters' request for comment. It says online that it believes the most effective way to combat misinformation "is to give readers the tools and information to scrutinize the media they consume."

The 38-year-old Simion's TikTok films combine nationalist rhetoric with an emotionally charged delivery and often use direct-to-camera speeches, footage from political gatherings and behind-the-scenes clips to hone a sense of personal connection.

It is a recipe perfected by Georgescu and other political parties are copying this style, Ionita said.

REAL ANGER

Ionita added that much of the suspicious content on online accounts reflected real anger in society. "They probably amplify the noise, but the noise is mostly generated internally," he said.

Benefiting from a wave of popular frustration against mainstream leaders, Simion opposes military aid to neighbouring Ukraine, is critical of the EU leadership and says he is aligned with the U.S. president's Make America Great Again movement.

While the interior ministry said on Monday that it had not observed any significant irregularities during the voting process, it said it remains vigilant.

James E. Trainor III, Commissioner of the U.S. Federal Election Commission which is observing the Romanian election, told Reuters in Bucharest that authorities had to "walk a very fine line" when regulating social media so as not to curtail people's ability to communicate.

"The best way for this process is to do exactly what (Romanian election authorities) are doing, and that is to talk directly to the people that run those sites," he said.

(Reporting by Malgorzata Wojtunik, Krisztina Fenyo, Elizaveta Gladun, Luiza Ilie, Editing by Alan Charlish, Alexandra Hudson)