He claimed that for every district covered under the yatra, Rs 10 crore was spent from the public exchequer.
However, the ruling Janata Dal (United) dismissed the charge as "sheer frustration" of the RJD supremo, who is facing trial in several corruption cases and convicted in one.
Addressing a press conference, Mr Yadav distributed copies of a purported order issued by an official of Jeevika, a state government project for providing employment to rural women.
As per the order, "4,000 women would participate in every public meeting of the CM during 'Vikas Samiksha Yatra' and would be paid Rs 75 each apart from the conveyance.
"This is in addition to expenditure incurred on security arrangements, allowances to officers, arrangements for public meetings etc.," Prasad, who was accompanied by senior party leader Shivanand Tiwary, claimed.
"This is turning out to be Vikas Samiksha Yatra ghotala (scam). At least Rs 10 crore is being spent in every district during CM's Samiksha yatra," he alleged.
"If the 'yatra' was so indispensable, the CM should have taken only security personnel along," Mr Yadav said, wondering why review meetings were being held in districts, away from the state capital.
He also alleged that flags of the JD(U), of which Mr Kumar is the national president, were being displayed at the public meetings funded by the state.
"There should be a probe into how much money has been spent on the CM's yatra," Mr Yadav said.
Mr Kumar is on a state-wide 'Vikas Samiksha Yatra' since December 12 to take a first-hand account and review the progress made in various districts on development schemes launched by his government over the years.
Mr Yadav also reiterated his earlier claim that Mr Kumar's standing in his own government has diminished and JD(U)'s junior ally, the BJP, was establishing a "firm grip on the government and administration".
JD(U) chief spokesman and MLC Sanjay Kumar Singh, however, said, "It is sheer frustration of Lalu Prasad...a person, who is convicted in a corruption case, is levelling charges against a man known for his honesty and probity".
Mr Yadav also dismissed exit polls predicting a BJP victory in Gujarat and claimed that the Congress would form government in the state and "all the exit polls will prove to be wrong like they did in Bihar in 2015".
On Sonia Gandhi's "retirement", he said, "She may not hold a post but will continue to give her guidance."
The RJD chief also added that Rahul Gandhi's elevation as the Congress president will "strengthen the Grand Alliance".
He also opined against the draft law banning instant triple talaq with provision of three years imprisonment for violations, saying "the Centre is behaving like an autocrat, taking steps as per whims and fancies".