The head of police in the Democratic Republic of Congo has been suspended following the death of a human rights activist, officials say.

Three police officers have also been arrested and the president is determined to resolve the case, the interior minister said.

Floribert Chebeya, head of the group Voix des Sans Voix, was found dead in his car near Kinshasa on Wednesday.

He had reportedly been due to meet the police chief that evening.

Both the police and Voix des Sans Voix have said the meeting never took place.