Police were set to arrest a 37-year-old guard at the Osaka Detention House on suspicion of taking bribes from a gang boss, police sources said Saturday.
The guard is suspected of taking money from the 66-year-old boss of a gang affiliated with the Yamaguchi-gumi, Japan's largest crime organization, in July 2004 and receiving a car from him three months later.
In return, the guard is believed to have done favors for the gang boss while he was being held on a charge of blackmail, the sources said.