Residents of a suburban Cardiff street have been reassured it is not a crime hotspot as shown on a police website.
Banastre Avenue in Gabalfa has only 14 homes but online crime mapping suggests it has an average of 19 crimes a month.
Ward Broughton, who made the discovery, said he was worried it might put off potential house purchases.
Police say the street had only one crime reported in three months and admit its figures included crime at the University Hospital of Wales.
Mr Broughton, a 40-year-old teacher, was consulting the recently launched www.police.uk website for information about crime in the area.
He was surprised to find his street branded with a crime rate similar to the busiest parts of Cardiff city centre.
"Banastre Avenue comprises only 14 houses, no pubs, no clubs, not even a takeaway," he said.
"Yet for three months in a row it has had well above average reported crime."
In December 2010 the map showed 12 crimes reported in the vicinity of Banastre Avenue, with 16 in January 2011 and 19 in February.
Five crimes in both January and February were described as violent.
Mr Broughton claimed that in an area with an incidence of 77 to 94 crimes per 1,000 people his street of around 30 residents was tagged with a crime rate equivalent to 400-600 per 1,000.
"I live on Banastre Avenue and I am certain that the level of crime and violence is nowhere near the published figure, but I can't understand why the figures are so wrong," he said.
Mr Broughton pointed out that nearby Whitchurch Road - a busy commuter route with a string of shops, takeaways and bars - shares the same postcode but has its own separate statistics.
However, he'd noticed that the University Hospital of Wales - visible from his house over the A48 Eastern Avenue - appears on the map to be a crime-free zone.
"There are no crime statistics for the Heath hospital at all - I can only assume that we are getting hit with the whole of A&E's Saturday night revelry," he said.
"I don't know if the figures would directly affect insurance, but they would put off potential house purchasers."
South Wales Police said the force did not consider Banastre Avenue to be a crime hotspot and admitted its crime figures covered a wider area.
"Mr Broughton's theory was correct - all crimes from the University Hospital of Wales were coming up as taking place in Banastre Avenue as it was the closest so-called 'snap point', said a spokeswoman.
"A new snap point for the hospital will solve this problem and will be included for next month's data."
Responding to this, Mr Broughton said: "It's good news - I'm just glad it's all sorted and that people will know we live in a nice peaceful street."
The force confirmed that Banastre Avenue's only reported crime in the first three months of 2011 was a theft of car number plates.
The Home Office said that local police forces were responsible for the data and how it was mapped, with public privacy being an important consideration.
"In order to protect the identity of victims, crimes will continue to be mapped to an anonymous point on, or near, the point on the street where they occurred," said a Home Office spokesman.
"Forces continue to provide additional location indicators in public spaces, such as shopping centres or travel hubs, to ensure that crime in these areas can be mapped as accurately as possible.
"Forces will be aware of any anomalies and will be updating these in the future."