Around 1,300 CCTVs installed in military bases, including along the heavily fortified border, were removed, a military official told AFP.

During a routine check, it was discovered the equipment was made in China, but supplied by a Korean company.

The issue was "identified in the process of jointly diagnosing foreign equipment for the first half of this year to identify security vulnerabilities of foreign equipment introduced into the military," the Ministry of National Defence said in a statement sent to AFP.

At a briefing on Friday reported by local media, the military said these CCTVs "were found to be designed to be able to transmit recorded footage externally by connecting to a specific Chinese server".

"No data has actually been leaked."

According to Seoul's defence ministry, the Chinese-made CCTVs are being collected and replaced with domestically made models.

The equipment, some of which was first installed in 2014, was misrepresented by the supplier as having been made domestically, local media reported. The military may seek damages from the company.

A military source told South Korea's Yonhap news agency that the surveillance cameras "were not used to monitor the border with North Korea but for military training grounds and base fences".