An assistant returning officer was suspended on Saturday and a case registered against him after a large number of VVPAT slips were found on the roadside in Bihar's Samastipur district, said a statement.
The VVPAT slips were found scattered on the roadside near a college in the Sarairanjan assembly segment of the district.
The Election Commission swung into action after a purported video of it went viral on social media.
The statement issued by the Chief Electoral Officer's office said the district magistrate has been directed to visit the spot and inquire into the matter.
"As these are VVPAT slips of a mock poll, the integrity of the polling process remains uncompromised. The contesting candidates have also been informed by the DM. However, the ARO is being suspended for negligence and an FIR is being registered against him," it said.
An investigation has also been started, it added.
The first phase of the assembly polls in 121 seats took place on November 6.