North Korea executed a former cabinet official who was in charge of talks with South Korea, a news report said today.

It is the latest reported death sentence for a North Korean official over policy failures.

Kwon Ho Ung – Pyongyang's chief delegate from 2004 to 2007 for ministerial talks with Seoul's then liberal government – was executed by firing squad, Seoul's mass-circulation Dong-a Ilbo newspaper said, citing an unidentified source in Beijing.

South Korea's intelligence agency and the unification ministry, which handles relations with North Korea, refused to comment on the report.

The news came as tensions between the two countries continues to simmer over the sinking of a South Korean warship that has been blamed on North Korea. Pyongyang has denied involvement in the sinking, which killed 46 sailors.

Relations have been particularly rocky since a pro-US, conservative government took office in Seoul in early 2008 with a tough policy on Pyongyang.

The newspaper report said it had not confirmed when and where Kwon was executed.

In March, North Korea executed two senior economic officials over a botched currency revamp that forced markets to close temporarily and fuelled social tensions, according to Daily NK, a Seoul-based media outlet that specialises in the neighbouring country.

The North Korean won was redenominated in December as part of efforts to fight inflation and reassert control over its burgeoning market economy. That reportedly sparked unrest after many North Koreans were stuck with piles of worthless bills.

It is not unprecedented for the communist regime to execute officials for policy failures. In the 1990s, North Korea publicly executed a top agricultural official following widespread famine.