The power failure at Salt Lake Stadium during yesterday's World Cup qualifier football match between India and Japan has been attributed to 'the rat factor' by the West Bengal State Electricity Board.

While state Power minister Mrinal Banerjee refused to make any comment saying that he was still ascertaining the facts, a WBSEB official said engineers on duty at the stadium switched off the 132-KV substation supplying power to the stadium after they detected smoke billowing out of it.

"Though there was no problem in power distribution, the engineers decided to rectify the error during the half-time break," the official said. On inspection, the engineers found that a rat, which had come in contact with a live wire, had been electrocuted, leading to the smoke. Power supply was restored after they brought out the dead rat, the official said.

The entire stadium had plunged into darkness save for two generator-propelled emergency lights, and the beginning of the second half was delayed by 29 minutes due to the powercut.