South Korea's spy agency has said it had been unable to verify whether North Korea's defence chief was put to death.

On Wednesday, various members of the parliament said Seoul's National Intelligence Service (NIS) believed that Hyon Yong-chol had been killed by anti-aircraft gunfire at a shooting range in Pyongyang for treason. The MPs were briefed in a parliamentary committee meeting.

The grim details of Hyon's alleged death dominated headlines, but the NIS on Thursday stressed that his execution had never been confirmed.

"Hyon has been purged," an NIS spokesman told the AFP news agency.

"And there are intelligence reports that he might have been executed, but this has not yet been verified," the spokesman said.

The confusion is partly the result of the way NIS briefings to parliament are carried out and reported.

They take place behind closed doors, after which selected members of the parliament pass on the information to the South Korean media, resulting in several degrees of separation between the original NIS briefing and the resulting headlines.

According to the MPs, the NIS said Hyon was purged for disloyalty and dozing off during official events presided over by leader Kim Jong-Un.

If confirmed, it marks the most high-profile take-down of a top Pyongyang official, since the purge and execution of Kim's powerful uncle, Jang Song-thaek, in December 2013.

Source: AFP