Wellington's Rimutaka Prison is operating normally after it was placed into lockdown following messages on the prison's phone line alleging that a bomb would be placed at the site.
Police were called about 9.20am on Wednesday and attended the site with specialist search dogs and conducted a search.
"Police attended the site with specialist search dogs and conducted an extensive search of the site but no suspicious items were found. We will continue to help police with their inquiries," a Corrections spokesperson said.
The lockdown at the prison was lifted at 3.30pm.
