Prosecutors plan to announce an indictment against former New York City Police Commissioner Bernard Kerik on Friday, several law enforcement sources have told FOX News.

Federal prosecutors in New York have spent more than a year pursuing criminal charges against Kerik, reportedly including bribery, tax evasion, obstruction of justice, providing false information and conspiracy to eavesdrop. They intend to hold a news conference to announce the charges against the one-time nominee to be secretary at the Department of Homeland Security.

The Associated Press reported that Kerik will also surrender to federal authorities Friday to be arraigned on criminal charges. FBI and IRS officials have planned an 11:30 a.m. ET announcement in White Plains, N.Y.

Former New York City mayor and presidential candidate Rudy Giuliani, who endorsed Kerik in 2004 to lead DHS before Kerik was forced to withdrew his nomination, has stood by his former business partner's record in New York, even though Giuliani said he should have checked his background more thoroughly.

"I have pointed out that I think I made a mistake of not checking him out more carefully. But when you balance that mistake against all of the successes that we had and the reality that you make some mistakes and you make some correct decisions, I think the overwhelming record is a record of great success," Giuliani said Thursday morning during a campaign stop in Dubuque, Iowa.

Giuliani has said he does not know what implication the indictment would have on his campaign. His campaign declined to comment on the latest legal actions.

FOX News' Ian McCaleb and Mosheh Oinounou and The Associated Press contributed to this report.