Police cordoned off streets in the Phillipstown area of the city on New Zealand's South Island, with a bomb disposal team, ambulance and fire and emergency crews sent to the scene.
"Police have located a package containing a suspected explosive device and ammunition at a vacant address ... In Christchurch," district police commander Superintendent John Price said in a statement, Reuters reported.
An explosives disposal unit rendered the package safe and a 33-year-old Christchurch man was arrested, the statement said. The police cordon was later lifted.
The New Zealand Herald said police were called due to "threats about an explosive device".
Fifty people were killed and dozens wounded in attacks on the Al Noor and Linwood mosques during Friday prayers in Christchurch on March 15, the worst peace-time shooting in New Zealand history. Tuesday's incident was about a kilometer from the Linwood mosque.
Authorities have charged Australian Brenton Tarrant, 28, a suspected white supremacist, with 50 counts of murder.
The mosque attacks shook New Zealand to its core and prompted the government to quickly tighten gun laws.