The interior ministry said Friday it has inspected all early voting stations across the country ahead of the April 10 parliamentary elections and found spy cameras at 26 facilities as of 6 p.m.

The inspection took place a day after police detained a YouTuber in his 40s on suspicions of installing spy cameras at early voting polling stations in two cities -- Incheon and Yangsan --, where early voting will take place.

Police said they have found spy cameras at five stations in Incheon, west of Seoul, and four stations in Yangsan, 301 kilometers southeast of Seoul.

The YouTuber reportedly told the police that he wanted to monitor the National Election Commission's manipulation of turnout rates for early voting.

Early voting for the upcoming elections is slated for April 5-6.

Following the incident, the Ministry of the Interior and Safety inspected 1,966 voting stations nationwide and the National Election Commission (NEC) the remaining 1,599 stations.

Of the total, spy cameras were found at 26 places, including Seoul, Incheon, the southeastern cities of Busan, Ulsan, Daegu and Yangsan, and Gyeonggi Provice, which surrounds Seoul.

The places also included facilities to be used for vote counting for the April elections, or have been used for such a purpose in the past, according to the ministry.

"We plan to deliver the results of the emergency inspection to the NEC, and we know that the NEC will conduct additional inspections after the installation of early voting stations are completed next Thursday if needed," a ministry official said.

"We will have to see the results of the investigation to figure out the reason for the spy camera installations as police are currently looking into the case after identifying a suspect," the official noted.