The police said that they were nabbed from near the NCP office in Dombivili at about 4 pm after which cash worth Rs 1.21 lakh, stickers and banners of NCP "candidate" Anand Paranjpe were seized.
Those held had allegedly asked the auto drivers to put up stickers upto April 22 for which they would be paid Rs 2200, the police said.
Police Inspector Milind Patil of the Manpada police station told PTI late tonight that statements of those held have been been referred to the returning officer of the Kalyan Lok Sabha constituency. It is only after his opinion that the police would act, he said.
Since he is not NCP's official candidate so far, the returning officer's decision will be vital for police action.
Moreover, sources said that the three alleged NCP activists who were taken away for questioning are reported to have informed the police that they would show this expense in poll accounts and that auto drivers were accepting compensation as "fuel expenses".