Tokyo (CNN) A single, small slug has been blamed for a massive power failure that brought part of Japan's high-speed rail network to a standstill last month.

An estimated 12,000 passengers were delayed on May 30, after power was cut on lines operated by rail company JR Kitakyushu, in the country's southern Kyushu region.

The outage occurred during peak commuter time, at 9.40 a.m, forcing the company to cancel a total of 26 trains.

Japan is famous for its large network of efficient high-speed trains, which run the length of the country and carry thousands of passengers every day.

During a later inspection of the network's electrical equipment, the company's engineers discovered a dead slug, measuring about 2 to 3 centimeters (0.7 to 1.1 inches) long.

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