Police probing Mohini murder erect billboard

Police said this cap and the blue bag it was found in could be vital clues in their investigation. Photo / Supplied

Police hunting the killer of Auckland taxi driver Hiren Mohini are putting up a bill board in downtown Auckland.

It is the first time police have used a billboard to appeal for information on a specific crime.

Detective Senior Sergeant Hywel Jones said the billboard will feature an image of the man police believe is connected to the killing and owns a bloodied blue bag found near the scene.

"We're trying a range of methods to appeal to the public for information. The billboard space was vacant and its location ties in nicely with the fact we're appealing to Asian communities in the inner city to help us solve this mystery," he said.

Mr Jones said police have also made a DVD with a police advertisement on it and will take it around supermarkets and other shops for it to be played on in-store promotion screens.

Meanwhile the number of investigators has been boosted to 50, and police say they are making constant breakthroughs.

Mr Mohini, 39, died after he was repeatedly stabbed in the Auckland suburb of Mt Eden by a passenger he had picked up in the central business district.

Police would like to speak to a man of Asian appearance they believe may be involved in the killing.

Yesterday they appealed to the Asian community for help in tracing the killer, saying their inquiries showed many were unaware of the murder.

Asians made up nearly 30 per cent of the central Auckland population and it was vital they knew how important it was for police to get any information they might have about Mr Mohini's killer, police had said earlier.

Police also released security camera footage of an Asian-looking man captured on CCTV in the CBD before the killing.

He was carrying a bag similar to a distinctive bloodied blue bag found a short distance from where Mr Mohini died.

Detective Senior Sergeant Hywel Jones today said the bag and a distinctive black knitted cap in it could be vital clues in finding the killer. The cap had a large white logo outlined with three circles.

Mr Jones said the inquiry team was making good progress but wanted to hear from anyone who recognised the hat, the bag or the man in the security camera footage.

"Every day we are making little breakthroughs. The team has increased to 50 or so staff and there is no let up in the inquiries," he told Radio New Zealand today.

- NZPA and NZHERALD STAFF