Human Rights Watch says Congo has refused to renew a senior researcher's work permit, requiring her to leave amid tensions over November elections.

The organization said Tuesday that by revoking Ida Sawyer's work permit President Joseph Kabila's government is restricting human rights reporting before the elections. It said several other researchers have also been expelled.

The organization said immigration authorities renewed Sawyer's work permit in May, but annulled it later and then denied her a new visa.

Sawyer, in Congo with the organization since 2008, has researched human rights abuses by the government and has criticized its crackdown on those opposed to Kabila's attempts to remain in power.

Government spokesman Lambert Mende said the decision was made by immigration officials and that Sawyer was not considered persona non grata.