Councils are being urged to provide more sites for Travellers which could help police build trust with this community.
The Association of Scottish Police Superintendents (Asps) said landowners want the police to take "robust action to evict Gypsy-Travellers" from unauthorised camps on private land.
The situation "at least partly" contributes to the lack of trust between Travellers and the police.
Asps is calling for more local authority sites at which Travellers can set up camp.
Superintendent Gavin Buist, Asps vice-president, is due to raise the matter with MSPs on Holyrood's Equal Opportunities Committee which is examining the accommodation available to Travellers.
In its submission to MSPs, Asps said the number of council-owned pitches fell from 560 in 2003 to 480 in 2006.
"This lack of provision of suitable sites for Gypsy-Travellers in Scotland creates knock-on problems for the police service in Scotland, particularly in relation to informal or unauthorised encampments."
A "relationship has never properly developed between the police and this particular community", Asps stated. "This situation can at least partly be attributed to the pressures which can be brought to bear on the police when Gypsy-Travellers occupy land otherwise than at an authorised encampment. This is particularly so where privately owned land is involved. Landowners expect the police to take robust action to evict Gypsy-Travellers."
Public perception of Travellers is generally negative and "tainted by criminal connotations", according to Asps, while pointing out that such views "do not always have a solid foundation in fact".
"Going forward, Asps would like to see the provision of more local authority sites with better facilities for Gypsy-Travellers in Scotland and better access to public services including health and education."