LOS ANGELES (CBSLA.com) — Paul Tanaka, a major candidate for Los Angeles County Sheriff, was under fire Tuesday.

According to the Los Angeles Times, Tanaka is a subject of an ongoing criminal investigation of abuse and corruption in the county jail system.

The 55-year-old was former under-sheriff at the department when an inmate, who was supplying tips to the federal government, mysteriously disappeared for a while.

Tanaka, who is running for sheriff against six other candidates, has denied any wrongdoing.