According to officials in the Income Tax department, Koda purchased and distributed around 600 bikes, 25 to 30 Scorpios, Boleros and other four wheelers to his supporters.
Sources said that IT sleuths searched two showrooms of motor bikes and four wheelers. They found that 200 bikes had been sold in one day from one showroom and have now sought help from the transport department to seek registration details.
Koda is charged with misusing his position as mines and geology minister and later as chief minister.
Koda allegedly sent a recommendation to the Central Government suggesting a list of names for the lease of 17 iron ore mines, sources said.
He used his influence to push certain private groups for the lease of coal blocks, an official said. The list is long, he added.
Koda is also accused of disposing of 40 files related to mines in just one day in Feb 2008.
"We are trying to unearth the channels through which money was generated and channelised inside the country and how they were sent to foreign countries. The focus of investigation is Koda and his associates," said an official, adding that they were acquiring new information every day.