The CBI on Thursday, summoned West Bengal Chief Minister Mamata Banerjee's election agent Sheik Sufian in connection with a murder case related to post-poll violence in Nandigram from where the Trinamool Congress' supremo had unsuccessfully contested.
The case is concerned to a fatal attack on Debabrata Maity by unidentified people in Nandigram on May 3.He succumbed to injuries 10 days later while undergoing treatment, they said.
Nandigram had seen a high-pitched electoral battle between Mamata and her confidante turned-rival Shuvendu Adhikari which was narrowly clinched by the latter.
Sufian, who was a TMC leader, has also been a complainant in connection with an alleged attack on Mamata during poll campaign.
CBI took over the investigation into the post poll violence on the orders of the Calcutta High Court.