North Korea has increased public executions, apparently in a bid to tighten controls amid the designation of North Korean leader's son Kim Jong-un as his father's heir. According to data released on Tuesday by Grand National Party lawmaker Yoon Sang-hyun, the regime publicly executed at least 22 people until the first half of this year since a botched currency reform late last year.

Yoon, a member of the National Assembly's Foreign Affairs, Trade and Unification Committee, obtained the data from an intelligence agency.

According to the data, the regime executed 10 people, including two women, on charges of robbery, rape and prostitution, all together in Pyongyang in December 2009. It also publicly executed the platoon leader of the border garrison on charges of narcotics smuggling and human trafficking the same month.

A noncom officer of the border garrison was executed in January for having aided and abetted the defection of a family and two Chinese Koreans for having leaked confidential information in February.

Yoon said a man who was publicly executed alongside Pak Nam-gi, the former director of the Workers Party Planning and Finance Department, in Pyongyang in March, turned out to be Ri Tae-il, then the first deputy director of the Workers Party's Organization and Guidance Department.

"When the currency reform, which the regime had hoped to tout as the achievement of Kim Jong-un, went wrong and people vented their complaints, it laid the blame on these two officials and executed them by a firing squad on espionage charges," Yoon added.

In March, two people were publicly executed for counterfeiting new banknotes, in April a platoon leader of the border garrison for aiding and abetting defectors and leaking military secrets, and in June two people for murder and another for human trafficking.

The figures are far larger than those in previous reports pub lished by Amnesty International, where it said the North publicly executed at least 23 people between 1970 and 1992 and "at least seven" in 2009.

The North for a while refrained from publicly executing people under increasing pressure from the international community, with AI releasing a special report on public executions in North Korea in 1997.