A Nelson man who held two victims at gunpoint - one for 15 hours - has pleaded guilty to charges of kidnapping and bomb threats

Phillip Clinton Mant was arrested after a stand-off at a Motueka Street property last August.

Prosecutor Mark O'Donoghue says the victims, including an 80-year-old man, believed they'd die if they didn't meet the 56-year-old's demands.

Mant wrote hundreds of pages of angry notes in the months before, and took a rifle, ammunition and an explosive device to the victims' street.

He's been remanded in custody for sentencing in July.