The Ministry of Employment and Labor will expand its probe of E-Mart over its alleged abuses of labor rights to 24 branches across the country, officials said Monday.

E-Mart, the country’s largest supermarket chain, is facing allegations that it had illegally monitored its workers to prevent them from joining labor unions.

The Labor Ministry conducted its probe into the head office of E-Mart last week, but decided to look into 24 branches nationwide to see whether they had also violated labor-related laws.

“During a special probe into E-Mart headquarters from (Jan.) 17 to 25, we discovered some labor law violations. We will look into 24 branches that are also suspected of illegal activity,” an official said.

“We will consider extending the inspection period or putting more branches on the probe list, if necessary,” he said. The official declined to comment on what specific violation the discount store committed, saying the ministry would announce the result of the investigation afterward.

The ministry will launch a report center to receive calls of any wrongdoings about E-Mart.

The ministry’s probe on E-Mart started last week, soon after Rep. Jang Ha-na of the main opposition Democratic United Party claimed that the retailer spied on workers under guidelines designed and delivered by its parent company, Shinsegae Group. The group distributed a list of ways to prevent workers from organizing or joining unions in June 2011 to all of its affiliates, a month before the government allowed workers to form multiple unions, the lawmaker said.

By Cho Chung-un (christory@heraldcorp.com)