Russian Foreign Minister Sergei Lavrov was taken to hospital because of a health concern following his arrival for the G20 summit in Bali, multiple Indonesian authorities say, but Russia denies he was hospitalised.
Russia's top diplomat arrived on the resort island the previous evening to take part in the meeting of the world's leading economies, which begins on Tuesday.
Russian foreign ministry spokesperson Maria Zakharova later denied that Lavrov had been hospitalised, calling it "the highest level of fakes".
She did not address whether he had received medical treatment.
She posted a video of Lavrov, looking healthy in a T-shirt and shorts, in which he was asked to comment on the report.
"They've been writing about our president for 10 years that he's fallen ill. It's a game that is not new in politics," Lavrov says in the video.
Russia's state news agency Tass separately cited Lavrov as saying: "I'm in the hotel, reading materials for the summit tomorrow."
Lavrov is the highest-ranking Russian official at the G-20 meeting, which US President Joe Biden, China's Xi Jinping and other leaders are attending.
Four Indonesian government and medical officials told the Associated Press that Lavrov was treated at the Sanglah Hospital in the provincial capital, Denpasar.
All of the officials declined to be identified as they were not authorised to discuss the matter publicly. Two of the people said Lavrov had been treated for a heart condition.
The hospital, Bali's biggest, did not immediately comment.
Russian President Vladimir Putin's attendance at the G20 had been uncertain until last week, when officials confirmed he would not come and that Russia would be represented by Lavrov instead.