The body of a senior Rwandan opposition politician, Andre Kagwa Rwisereka, who had been reported missing, has been found. <br/><br/>The Democratic Green Party said he had been found near his abandoned car and that his head had been almost completely severed from his body. <br/><br/>The party has been unable to register for presidential elections next month. <br/><br/>Human rights groups have accused the government of clamping down on the opposition before the vote.