A bomb threat from an overseas number recently sent Otago's prison into lockdown.
A well-placed source said police received the threat to Otago Corrections Facility on Tuesday afternoon last week via an overseas number.
Corrections deputy national commissioner Andy Milne confirmed that was correct.
There has been no official confirmation of the exact nature of the threat, received by police at 4.05pm, aside from that it was a bomb threat from an overseas number.
Mr Milne said the Milburn prison was not evacuated, but went into lockdown.