As complainant, Democrat Party executive Piraphan Saliratvipak submitted the records showing how the EC had bypassed existing regulations in order to print ballots in a suspicious manner. Piraphan said the flawed printing might result in the stuffing of ballot boxes as detected in Samut Sakhon.

He also filed evidence showing how the four-member EC had divided up responsibilities to supervise the balloting in each region without authorisation.

The additional evidence was part of the judicial review on the validity of the electoral process.

In Piraphan's complaint filed last month, he argued the election outcome should be cancelled because the EC required five members to supervise the balloting but it had only four incumbents.

In a related development, the Prachakorn Thai Party asked the court to name it as a co-accused in order to defend the election outcome. The party said it was one of the small parties contesting the polls and its interest was at stake if the balloting results were cancelled.