By Guy DeLauney
BBC News, Phnom Penh
Rights groups have criticised the government over forced evictions
The new UN Special Rapporteur for Human Rights in Cambodia, Surya Subedi, is making his first visit to the country.
Professor Subedi has said he wants to establish fruitful and constructive dialogue with the Cambodian government.
But his predecessors struggled to do that, and Prof Subedi's visit comes as civil society groups have said they are concerned about the rights situation.
The government has consistently defended its human rights record, noting recent democratic elections.
This is a chance for a fresh start in the relationship between the Cambodian government and the UN's human rights organisation.
But that may require diplomacy and patience on both sides.
Prof Subedi's predecessor resigned last year after enduring months of snubs and insults from the government.
Ministers declined requests for meetings, and one called the envoy a long-term tourist.
The new rapporteur is keen to avoid a repeat of that situation.
He has indicated that his first visit will concentrate on establishing contacts with key officials and it seems the government has been receptive.
But Prof Subedi will also be meeting the leaders of local organisations who say they are worried about recent developments in Cambodia.
The UN's human rights office in Phnom Penh has just issued a statement expressing concern about the use of defamation and disinformation laws to silence government critics.
Other organisations have criticised land grabs and corruption.
But the government has consistently defended its human rights record, pointing to the success of several democratic elections since the return of peace in the 1990s.