Lawyer Nikita Jacob and engineer Shantanu Muluk on Monday joined the probe in connection with the toolkit case and are being questioned at the Delhi Police's Cyber cell office in Dwarka, a senior police officer said.

The Delhi Police, probing the 'toolkit Google doc' backing the farmers' agitation shared by climate activist Greta Thunberg, had arrested Bengaluru-based activist Disha Ravi while Jacob and Muluk were granted pre-arrest bail by a court.

"Both Jacob and Muluk were served notice to join the probe and are currently being quizzed in connection with their alleged role in the toolkit case," the officer said.