BEIJING - Delegates and journalists witnessed drama at the usually staid closing session of the Communist Party of China’s congress on Saturday.

As local and foreign journalists, including from The Straits Times, filed into the Great Hall of the People, sitting before them on the main stage were China’s top leaders including President Xi Jinping. Beside Mr Xi was his predecessor Hu Jintao, 79.

The week-long party congress was about to come to a close, with Mr Xi another step closer to being anointed as paramount leader for a third term.

But just as journalists had taken their places – just before the 2,300 delegates would vote unanimously to endorse Mr Xi’s core leadership position – there was a hint that the event was about to go off-script, when a steward went over to Mr Hu and they spoke briefly. It is unclear what the conversation was about.

At one point, Mr Li Zhanshu, the party’s third-ranking official who was sitting to the left of Mr Hu, reached over and took the stack of documents in front of the former president.

Another steward then came over and persuaded Mr Hu to leave. A frail-looking Mr Hu appeared reluctant, even after one of the stewards pulled him up from his chair.

By now, it was clear that this was not part of the plan of what is usually a highly choreographed event.

As he was about to be escorted off the stage, Mr Hu said something to Mr Xi, who nodded. He also appeared to have said something to his protege, Premier Li Keqiang, who also nodded.

Mr Hu patted Mr Li’s shoulder as he left, as most of his party colleagues stared firmly ahead.

Mr Hu had attended the party congress as part of the presidium standing committee, the body that oversees the twice-a-decade congress. The 46-member committee comprises current leaders, as well as party leaders and retired senior officials.

Also part of the committee are former leader Jiang Zemin, 96, and former premiers Zhu Rongji, 93, and Wen Jiabao, 80. But both Mr Jiang and Mr Zhu, who are believed to be in poor health, did not attend the congress.

A clip of the awkward moment involving Mr Hu, posted on Twitter by The Straits Times, has gone viral, with more than nine million views.

China watchers pored over the 85-second-long footage, with some saying Mr Hu had been made to leave after a disagreement with Mr Xi.

The end of the party congress would reveal that top officials including current Premier Li Keqiang and Mr Wang Yang, who heads the top advisory body to China’s Parliament, would not be in the party’s new Central Committee.

Both men are seen to be part of the Communist Youth League faction, to which Mr Hu belongs.

Others say Mr Hu, who is rumoured to be in poor health, had perhaps left because he was unwell.

The debate underscores how Chinese elite politics have become opaque under Mr Xi, who has clamped down on leaks. Tidbits like this can offer rare insights into happenings within the party.

But while the clip has spawned heated debate outside of China, there has been no mention of it on Chinese social media, which is heavily censored.

State news agency Xinhua wrote in a tweet late on Saturday night that Mr Hu had left because he was “not feeling well”.

“His staff, for his health, accompanied him to a room next to the meeting venue for a rest. Now, he is much better,” said Xinhua.