The threat was made late on Wednesday morning.
Said MSD regional commissioner Diane McDermott: "MSD service centres in the Canterbury region are re-open and resuming regular services after being placed into lockdown today.
"Police were called following an incident involving an alleged threat made against our staff in the Canterbury region.
"When security incidents occur at our MSD offices, we have a standard process we follow to protect staff, clients, our security guards and members of the public.
"We followed this process and put all our offices on lockdown until the matter was resolved.
"The matter has now been resolved by police and we are resuming to regular service. We would like to apologise for the inconvenience caused to our clients during the lockdown and encourage anyone needing help to give us a call on 0800 559 009 or use their MyMSD app," she said.
A police spokesperson said they responded to a report of a threat made to an address on Munich Pl, Bromley, which was placed in lockdown as a precaution.
Police are speaking to a person relating to the incident and all cordons have been lifted.
