Ugandan journalist Andrew Mwenda has been charged with sedition after a radio debate speculating on the death of Sudan's vice-president John Garang.
Andrew Mwenda (l) is due in court on Monday
The authorities also closed KFM radio which aired Mr Mwenda's chat show.
The Ugandan government has warned it will act against journalists who endangered national security.
The Sudanese ex-rebel leader died in a helicopter crash on his way back from talks in Uganda on 30 July. Sudan has repeatedly said it was an accident.
Uganda's Information Minister Nsaba "reminded" journalists on Saturday in an article in the Monitor newspaper "that even where facts may be true, reporting must be informed by an imperative to preserve national interests."
Mr Mwenda's show on Wednesday aired hours after President Yoweri Museveni had warned the media not to report speculation about the crash.
The decision to close the station the following day has angered opposition leaders.
Politician James Otieno told the BBC the move was "unacceptable", while the Uganda Journalist Association said the government had exceeded its powers.
Conspiracy theories on Mr Garang's death ranging from sabotage to hijackings have raged in the Ugandan media.