CBI Special Judge K P Jothindranath ordered the accused to appear before the court on September 24.
He also ordered the CBI to conduct further investigation into the role of former Kerala Power minister G Karthikeyan and state Electricity Board member R Gopalakrishnan, who were excluded in the charge sheet filed on June 11.
"I order further investigation as no charge sheet had been filed against the persons described as accused in the final report on the ground that mens rea (intention or knowledge of wrongdoing) is lacking and evidence is not forthcoming," the judge said.
In the charge sheet, CBI had listed Vijayan as the seventh accused in the case relating to alleged corruption in awarding of contracts to Canadian firm SNC Lavalin for renovation of three hydel projects in 1998, when Vijayan was Power minister.
The charge sheet was filed after Kerala Governor R S Gavai gave sanction to prosecute Vijayan, overriding state cabinet's recommendation against it. Gavai's sanction had stirred up a controversy with ruling CPI-M describing it as "politically motivated". But striking a discordant note, Chief Minister and Vijayan's arch rival V S Achuthanandan virtually endorsed it, saying Governors had discretionary powers to sanction prosecution.
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