A senior North Korean official appeared at an arts performance with the country's top brass, official media reported, just three days after he was said to have been purged following the collapse of nuclear talks between leader Kim Jong-un and US President Donald Trump.

Kim Yong-chol, the North's counterpart to Secretary of State Mike Pompeo in the nuclear negotiations, was sent to a labour camp after the Kim-Trump summit in Hanoi in February, South Korea's Chosun Ilbo newspaper had reported on Friday.

The paper had also made worldwide headlines by saying that Kim Hyok-chol, North Korea's special envoy to the United States, had been executed by firing squad in March, after the two leaders failed to come to a deal over sanctions relief and the North's nuclear programme.

Kim Hyok-chol was Pyongyang's counterpart to US special representative Stephen Biegun in the run-up to Hanoi, and the Choson Ilbo said he had been put to death for "betraying the Supreme Leader" after he was "won over to the US" during pre-summit negotiations.

But the North is difficult to report on as one of the world's most isolated nations and some previous Southern reports of purges and executions by Pyongyang have later proved inaccurate.

Today, the North's official Rodong Sinmun newspaper carried a picture showing Kim Yong-chol sitting five seats down from North Korean leader Kim Jong-un, with both his hands covering his face, at a "performance given by amateur art groups of the wives" of military officers.

Kim Young-chol seen at the far right with his face in his hands, according to Rodong Sinmun

The South's Munhwa Ilbo afternoon paper carried the photo on the front page of its Monday edition, with the headline: "Kim Yong Chol, rumoured to be purged, affirms his position next to Kim Jong Un".

But there was no sign of Kim Hyok-chol, the official said to have been executed, in the Rodong Sinmun picture, nor was he mentioned in the official Korean Central News Agency's report on the event.

Chung Seong-chang, a senior researcher at the private Sejong Institute, said Pyongyang had probably issued the report and pictures in response to the Choson Ilbo report.

Kim Yong-chol had not been seen in public for some time, but rather than being purged he had undergone surgery to remove a malignant tumour, Mr Chung said, adding he obtained the information from a person who regularly contacts North Koreans.

South Korea's parliamentary intelligence committee in April said Kim Yong-chol had been censured over his handling of the Hanoi summit, despite the fact he had recently been named a member of the State Affairs Commission, a supreme governing body chaired by Kim Jong-un.

The report of Kim Hyok-chol's execution was "likely to be false", Mr Chung said, citing information he had received that Mr Kim was seen in mid-April, although he declined to disclose his source.

"No one would dare to take part in nuclear talks if Kim Jong-un sends officials to hard labour, political prison camp or executes them if talks fail," he said.