According to a senior Commission functionary, who did not wish to be quoted, it is for the first time an EVM underwent such a test.
EVMs had replaced the ballot paper nearly 20 years ago.
In May, the Bombay High Court had ordered examination of the EVMs from the Parvatti constituency in Pune. The order was issued to rule out tampering during elections to Maharashtra legislative assembly in 2014.
One control unit, one ballot unit and two batteries were sent to the lab. An EVM comprises a control unit and a ballot unit.
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As per the report received from the lab, the machine is a stand alone, non-networked, one-time programmable unit, which is neither computer controlled externally nor could be connected internally or to any network.
The report was made public after being submitted to the high court.
After the declaration of assembly poll results of Uttar Pradesh, Punjab, Goa, Manipur and Uttarakhand, some parties had raised concerns over the credibility of EVMs used by the EC and had alleged tampering of the machines during the elections.
In April, 13 parties had met the Commission and had urged it to revert to the old ballot paper system. After an all- party meet on the issue, the poll panel had organised a challenge to tamper with its EVMs. But no political party took part in the June 3 challenge.