We have achieved high-pressure resistivity measurements on NpTe single crystal up to 21 GPa. We observe the phase transition from NaCl to CsCl phase at 13 GPa and the decrease of antiferromagnetic transition temperature T_N from 41 K to 2 K. In the NaCl phase, insulator behaviour develops: it could be described by a simple activation energy law. At the phase transition, a metallic behaviour replaces insulator behaviour with a large decrease of resistivity. Simultaneously, a sharp collapse of resistance appears at very low temperature. The origin of this collapse in the CsCl phase at T\sim 5 K is still unknown.

PACS numbers: 72.15.--v, 75.30.Mb