Singh had gone underground after resigning from the board two weeks ago ever since his name figured in the Class 12 toppers' scam.
Mobile internet services have been suspended in the state for the next five days.
Kumar has been arrested from Jharkhand's Hazaribagh district, a senior police source said, adding of the four others arrested along with Kumar, two are his nephews.
The Congress unit described Ramesh's suicide an outcome of "targeted harassment" of their rank and cadre to keep them away from the party.
'He is in a wheelchair, his joints are swollen and he is in great pain.' A Ganesh Nadar/Rediff.com speaks to colleagues and students of the polio-afflicted Delhi University Professor G N Saibaba, who was arrested on May 9 for alleged Naxalite links.
