The top UN human rights official in the Democratic Republic of Congo has left the country after the government ordered his expulsion for publishing a report accusing the police of abuses, but a UN spokesman said on Sunday he would return.

Spokesman Carlos Araujo confirmed that the UN mission had received an official request from President Joseph Kabila's government for the departure of Scott Campbell, the director of the United Nations Joint Human Rights Office.

Araujo said Campbell had left the country on Friday for a long-scheduled vacation.

"As he is on leave, we are expecting him to come back to the DRC," Araujo said in an email.

Government spokesman Lambert Mende told Reuters that Campbell could not return to Congo in his capacity as UN director of human rights. If he wanted to return as a private individual, that would be a matter for Congo's consular offices to determine, Mende said.

The interior ministry on Thursday demanded that Campbell leave after publishing a report that accused police of executing civilians during an anti-gang operation in the capital Kinshasa.

Interior Minister Richard Muyej rejected the report's findings at a news conference on Thursday, where he accused Campbell of seeking to destabilise the government and declared him "persona non grata".

The head of the U.N. mission in Congo, Martin Kobler, expressed his full support for Campbell in a statement on Saturday and urged the government to reconsider its decision.