A North Korean official who was reported to be in a labour camp attended a weekend concert alongside Kim Jong-un, state media said.
Last Friday, Kim Yong-chol was widely reported to have been sent to a re-education camp as punishment.
North Korean media showed him apparently at a musical performance with other officials.
A list of attendees identified him as present, though a picture showed his face partly obscured by his hands.
Kim Yong-chol, a former spymaster, has been described as the North Korean leader's right-hand man.
He travelled to the US in January to prepare for the second summit meeting between Mr Kim and President Trump, which was held in Vietnam.
Friday's reports that Kim Yong-chol had disappeared began with an anonymous source quoted in a South Korean newspaper. The paper also said that Kim Hyok-chol, a former North Korean envoy to the US, had been executed at an airport in Pyongyang.
Kim Hyok-chol was another key figure in talks ahead of the US-North Korea summit held in February.
Though he was not among the attendees listed for Sunday's event, state media have not yet reported any execution or punishment so his whereabouts remain unclear.
Was Kim Yong-chol really sent to a labour camp?
Kim Yong-chol's reported attendance at Sunday's concert does not guarantee that he was not blamed or punished for the collapse of the Vietnam talks.
"I wouldn't be surprised if he was demoted," North Korea expert Andrei Lankov of Seoul's Kookmin University told the BBC. "But he was seen quite alive on Sunday and that means he is still in a position of power.
"Had he been in prison or in a labour camp, he would never have been allowed to be seen at an event like this."
Asked if there was any doubt over the state media account, Mr Lankov replied: "He was pictured at the official photo, he was mentioned by the KCNA (Korean Central News Agency). They have no reason to engage in complicated charades."
It can be difficult to verify reports that high-ranking North Koreans have fallen from favour and been purged or executed - and such claims often prove inaccurate.
South Korean media and the government in Seoul have alleged purges in the past, only for the individuals to turn up alive and still alongside Kim Jong-un.
Singer Hyon Song-wol is a prominent example. In 2013 she was alleged to have been shot in a "hail of machine gun fire while members of her orchestra looked on".
In 2018 though, the singer appeared in Seoul leading a visiting North Korean delegation ahead of the Winter Olympics.