South Korea's plan to deploy a surveillance blimp near the northwestern border has been delayed due to errors in its data transmission system, the state arms procurement agency said Sunday.

The Defense Acquisition Program Administration (DAPA) spent 24 billion won (US$21.9 million) to build an airship with imported parts to monitor the North Korean military near the tensely guarded border. 

The moored blimp, equipped with an optical camera, radar and a ground control system, was delivered to the Marine Corps in May.

But the blimp recently failed to properly send its data to the ground control equipment, further delaying the deployment that was scheduled for August, a senior DAPA official said.

Seoul decided to add the surveillance drone to the air shield near the border one month after the North shelled a frontline western island in November 2010, killing four South Koreans.

The DAPA signed a deal with a U.S. venture firm, a main contractor, in July 2011 with the goal of deploying it in 2012, but the schedule has been repeatedly delayed due to faulty parts. (Yonhap News)