Nigeria
Despite being being one of the UK Governments 'safe' countries, reports are common of Nigerians being subject to human rights violations, including police torture and extrajudicial executions of detainees. Three out of five prisoners in Nigeria are untried. With government officials at all levels generally believed to be committing serious abuses, the state is regarded by many as effectively corrupt and lawless.
You can find out more info from the UNHCR here