A man was arrested after ammunition was found during a major police operation at offices used by the Housing Executive in north Belfast yesterday.
It is understood ammunition was found in an office used by concierge officials based in a New Lodge tower block.
It is believed the large scale raid centred on several tower blocks and involved the PSNI helicopter.
Police last night said a 55-year-old man was arrested on suspicion of possession of ammunition in suspicious circumstances and taken to Musgrave Police Station for questioning.
He was later released on police bail pending further enquiries.
It is believed the man lives in the area and is not a member of staff.
A PSNI spokesman said yesterday that police were "conducting a number of searches" as part of an "ongoing investigation into serious crime".
"A number of items, including a quantity of suspected ammunition, seized during the operation have been removed for forensic examination," he later added.
In January a number of rounds of ammunition were found during a search in the Eithne House tower block in New Lodge.
Sinn Féin councillor JJ Magee last night welcomed the find.
"I welcome the fact that ammunition which was found following an extensive search in the New Lodge area has been removed from our streets," he said.
"There can be no place in our society for anyone who would bring guns onto our streets.
"The community is a safer place following the removal of this dangerous material."
The Housing Executive declined to comment.
