Wellington, Oct 13 NZPA - The Government is urging people to use a new, anonymous hotline to tip off the police about criminals.

Police Minister Judith Collins launched the Crimestoppers phone line yesterday, saying criminals intimidated witnesses and victims who would otherwise speak out.

"The police, and others who serve within the justice system, are only as effective as the information they receive," she said.

"As it has done so successfully in many countries overseas, Crimestoppers provides a safe, anonymous channel by which people can speak out and speak the truth."

Police Commissioner Howard Broad said it would lead to more crime being reported and criminals arrested.

It was independent of government, police and other law enforcement agencies.

"Information flow is the lifeblood of policing and experience in the United Kingdom has shown Crimestoppers is very successful in helping police to identify both crimes and criminals," Mr Broad said.

"The Crimestoppers' guarantee of anonymity provides a way for people to feel safe about passing on what they know, so we're likely to receive information of a type we haven't had before and from people who would not normally come forward."

He encouraged people who were willing to be identified to continue to approach police directly.

"Crimestoppers does not detract from the general public duty to help police by giving information directly as informants or witnesses and we have a long and successful history of the public coming forward to do that," Mr Broad said.

People should continue to call 111 in emergencies and *555 to report traffic matters, while non-urgent crime should be reported to local police stations.

From 4pm yesterday people could call the new number 0800 555111 or submit an encrypted on-line form via www.crimestoppers-nz.org.

Britain's Lord Michael Ashcroft attended the launch in Auckland.

Lord Ashcroft established a Crimestoppers line in Britain in 1998 and it has led to more than 80,000 arrests, paying rewards in some cases.

His $200,000 reward led to the return of 96 war medals stolen from Waiouru Army Museum in 2007.

Yesterday he offered a $50,000 reward for information leading to a conviction in the Aisling Symes case -- hours before police confirmed they had found the body of a young girl in a drain near where the two-year-old went missing a week ago.