The four-hectare block was placed on the National Trust Register of Significant Places as a rare example of a small rural police station and residence predating the development of the federal capital territory.

In its decision, the trust said: ''The design and construction of this Federation building is unique in the ACT as the only remaining Federation building which existed prior to the development of the Territory.''

The listing states that ''elements of the historic landscape that provide an appropriate setting for this place, including the current driveway access, are to be retained. The current boundary is to be retained with provision for possible future extension of the place to the original boundaries of the land (ie Portion 67) so as to enhance the rural setting.''

But the ACT government has dismissed concerns about turning a paddock on the site into a bike trail.

''The site of the Old Ginninderra Police Station, including the dirt bike track, is being managed in compliance with heritage and lease conditions,'' a spokeswoman said.

''The track is away from the buildings and does not impact on the heritage values of the site. It does, however, provide a safe and supervised activity for young people.''

The National Trust ACT ceased classifying places in 2004, instead nominating them to the ACT Heritage Register where, if accepted, they would be afforded a level of statutory protection under the Heritage Act 2004.

Senior manager of Barnardos Canberra, Annette Kelly-Egerton, said the charity had sought advice from the ACT government when concerns where first raised in 2012 about the use of the property.

Ms Kelly-Egerton said she had an email from the Department of Sustainable Development approving the dirt track and advising that it did not adversely impact on the heritage value of the site.

''According to the ACT we are compliant,'' she said.