The National Land and Property Gazetteer (NLPG) will underpin the National Land Information Service (NLIS) - an online search facility for land and property information.
Earlier this month software suppliers and local authority IT professionals claimed that 20% of the data in the NLPG could be inaccurate. Both Intelligent Addressing - the supplier helping local authorities to feed data into the system - and joint NLIS project leader Local Government Information House denied this.
Intelligent Addressing has insisted that data in the NLPG is overwhelmingly accurate. The entire NLPG achieved a 97% match rate against land registry records, it said. However, the company has refused to reveal details of its survey.
"You have got no way of judging their claims about the NLPG until it is opened up to independent testing and scrutiny," said Bob Barr, senior lecturer in geographic IS at Manchester University. "No one knows whether it is better or worse than what we had before."
Robert James, a consultant in address data management, said an independent examination of the NLPG could be carried out by an accountancy firm or computer industry body, given the necessary technical support.
Intelligent Addressing would not comment on whether it would allow an independent survey into the NLPG. It said that its customers were satisfied with the database and that quality control arrangements were mandatory.