"Paani ki tarah paisa bahana bhi kam hoga kahna jitna kharchila prachar kar ke chunav jeeta BJP ne (free flow of money would be an understatement to describe the magnitude of money power used by BJP to win election)," Kumar said addressing political meeting of JD(U) workers at Punpun here.
Kumar said BJP "exploited anti-incumbency against UPA government to the hilt with the help of money by launching an advertisement campaign."
Kumar, who quit the post of Chief Minister of Bihar in the wake of severe drubbing in the general elections, said "It was beyond anybody's imagination to match the advertisement campaign of BJP backed by hefty money power."
Kumar was winding up his 16-day 'Sampark Yatra', considered preparations for the coming Assembly polls, with a meeting at Punpun in Patna district.
During his Yatra, Kumar travelled 4,400 km and addressed 31 political meetings of JD(U) workers in 33 districts in the state.
He played Prime Minister Narendra Modi's speech on black money and special category status for Bihar to highlight BJP "going back" on promises on this count.