New Plymouth detectives want public help with an investigation into a savage aggravated robbery which left a man bruised and battered on Monday.

Detective Sergeant Greg Gray said the 52-year-old man had returned to his Rawhiti St, Vogeltown, home late afternoon and was attacked by two people in disguise who had broken into the home.

They punched and kicked the victim before tying him up, questioning him and them beating him with what appeared to be an iron bar when they didn't get the answers they wanted.

Mr Gray said the pair left in a grey, 1995 Nissan Terrano which the victim had been using, and it was found later in the evening in a paddock on Cross Rd in Lepperton, 17km southeast of New Plymouth.

Detectives were working on the case, which had some mysterious aspects to it and few leads.

Investigators were keen to hear from anyone who may have seen the Terrano between Rawhiti St and Lepperton from 5pm to 8pm on Monday.

Police were particularly interested in speaking to three or four people seen in the Waitara Rd/Cross Rd area south of Waitara shortly before 8pm on Monday, with a blue Ford Laser hatchback and a red or maroon hatchback with its bonnet up.

The victim was recovering with friends after getting hospital treatment for head and arm injuries.