The letter claims the girl's body was buried on Kaiti Hill in Gisborne.
An American teenager was murdered and her body buried on Kaiti Hill, letters sent to police and The Gisborne Herald newspaper claim.
Police have started an inquiry after receiving the letter three weeks ago.
The Gisborne Herald received a similarly-worded letter yesterday.
Both letters were date-stamped Rotterdam.
The Herald letter was written in black felt tip pen on a piece of white A5-sized paper in poorly-worded, capitalised and misspelt English.
The writer claimed a girl was murdered and buried on Kaiti Hill. She was 14 or 15 years old.
Gisborne police received a similar letter but without the girl's nationality and age.
"We are currently making inquiries to determine the veracity of the letters," said Detective Sergeant Daniel Kirk.
"There is no information about the disappearance of a person of that age, gender and nationality anywhere in New Zealand.
"It would of course have been very helpful if the letter writer had provided some identification."
The letters were not signed and had no return address or contact details.
"We would urge that person, if they are a subscriber to The Gisborne Herald online service, to contact us directly," Kirk said.
"They can either do that through their local police in Holland or directly to New Zealand Police through any of our online platforms."
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