JOHANNESBURG (AP) — A leading media advocacy group is calling on Congolese authorities to release a journalist who was sentenced in December to six months in prison on defamation charges.

The Committee to Protect Journalists said Saturday that Joachim Diana Gikupa, editor of daily newspaper La Colombe, should be released pending an appeal. U.N. radio Okapi reported that Gikupa’s lawyers filed an appeal saying he was in poor health.

CPJ says that Gikupa was convicted of criminal defamation for publishing a report alleging that a Chinese company managing a local hospital had sold expired medication, among other things. It condemned Congo’s use of criminal defamation charges to jail journalists for critical reporting.