The Central Bureau of Investigation carried out surprise searches in two residential flats at R.T. Nagar and Dinnur here early on Sunday and arrested 13 candidates who were in possession of question papers for the Assistant Railway Loco Pilot exam scheduled later in the day.

The aspirants from Karnataka and Tamil Nadu, besides a few from North Indian States, were busy preparing for the exam with the help of the leaked question papers in the apartment when the CBI sleuths knocked on their doors.

The candidates had begun preparations on Saturday, a day in advance, said a CBI official, who was part of the team that carried out searches based on a tip-off.

The aspirants had allegedly paid Rs. 5 lakh each to get the question papers in advance from a few Railway officials, who had also arranged their accommodation at an apartment in R.T. Nagar and Dinnur to not only help them prepare for the exam, but also avoid further leakage, sources said.

Based on the information provided by the candidates, the sleuths also raided the houses of Divisional Personnel Officer of South Western Railways Shivanna, who had allegedly played a key role in the racket. However, Shivanna managed to escape.

The officials raided the house of Chief Vigilance Inspector of South Western Railways Mahesh and arrested him along with his associate Shivaramaiah, a city-based advocate.

Efforts are on to arrest Shivanna, a senior CBI officer said.

The officials have recovered a few documents and Rs. 1.5 lakh in cash from these two. A case under Sections 120B and 420 of the IPC and under various sections of Prevention of Corruption Act have been registered against them, a senior officer said.

Meanwhile, the Railway Recruitment Board conducted the exam as per the schedule. Senior officials of South Western Railways feigned ignorance about the raid when they were approached for their comments.