PHOENIX — In a bombshell revelation, Sheriff Joe Arpaio acknowledged Thursday that his office was behind a secret investigation into the wife of the judge presiding over a racial-profiling lawsuit against the brash Arizona lawman known for his anti-immigration patrols.

A contempt-of-court hearing in the case took the strange turn after the sheriff finished his testimony and Judge Murray Snow began asking him questions, including whether Arpaio was investigating him and his family.

“Are you aware that I’ve been investigated by anyone?” the judge asked.

Arpaio said he believed his former lawyer, Tim Casey, had hired a private investigator to investigate Snow’s wife after she purportedly made a comment that about the judge not wanting the sheriff to get re-elected in 2012.

“We weren’t investigating you,” Arpaio told the judge. “We were investigating some comments that came to our attention.”