The FIR was lodged by a vigilance department team of Faizabad at Akbarpur Kotwali police station on Wednesday, its Station House Officer Nagendra Singh told reporters.
The BSP leader was booked under the Anti Corruption act, the SHO said.
The Lokayukta had on March 14 recommended CBI or vigilance inquiry against Rajbhar, who was Transport Minister in the previous Mayawati government.
On April 1, the state government ordered a vigilance inquiry against the former minister.
The Lokayukta had also recommended that an FIR should also be lodged against the BSP state president under Anti Corruption act on the charges of disproportionate assets and money laundering.
Lokayukta's recommendations were made on a complaint registered by one Anand Kumar Dwivedi, who had accused the former minister of acquiring assets in the name of his relatives beyond the known sources of his income.