North Liverpool's pioneering community justice centre risks being sidelined by public spending cuts, says a report.
The report has warned that it will be difficult for the Ministry of Justice to assess the centre's impact.
The authors of Doing Justice Locally said despite the interest shown at home and abroad in the centre, there was little hard data about its results.
Opened in 2005, the centre combines a court with a wide range of community services for victims and offenders.
Housed in a former school, the centre, based on a project in the USA, focuses on offenders making amends to the community with its judge also monitoring treatment programmes and community punishments.
But the report, produced by the Centre for Crime and Justice Studies, said the court's goal of "involving the community" has "proved a nebulous concept to apply in practice and raises wider questions about who should be involved, and how, and what do these engaged people do?"
It said given the project's status as a pioneering example of community justice, "it is surprising how thin the available evidence is about effectiveness of the North Liverpool Centre".
Report co-author George Mair said: "The centre offers an approach to community justice which the coalition government would do well to learn from."
His colleague Helen Mills added that the lack of robust data collection on impact will make it difficult for the Ministry of Justice to assess the centre at a time when budgets are being scrutinised.
The Centre for Crime and Justice Studies is a charity specialising in the research of crime and social justice issues.