Leigh Davids, who has been a sex worker for more than two decades, faces harassment, assault and rape daily. This is the reality faced by many sex workers. Some do not live to tell the tale.Records kept by the advocacy group Sex Workers Education and Advocacy Taskforce (Sweat) show that at least 30 sex workers have been murdered since July. Many were found "strangled and mutilated" with multiple stab wounds.Davids says not a day goes by when she doesn't fear for her life."I have been locked up in rooms by clients, I have jumped out of moving cars... I get into sticky situations where I have to fight my way out," she says.Sweat's records show that besides the 30 deaths, the organisation has documented 697 human rights violations against sex workers, which include rape, murder, assault and harassment by police and clients.Cherith Sanger, advocacy manager at Sweat, said the numbers could be much higher as many of these violations went unreported.The rights of sex workers have come under the spotlight after renowned artist Zwelethu Mthethwa went on trial in the Cape Town High Court.He is accused of murdering sex worker Nokuphila Kumalo, 23, in April 2013.Mthethwa has pleaded not guilty and is out on bail.Last week, the trial came to a halt as the authenticity of CCTV footage expected to reveal the attack on Kumalo was questioned by the defence.Judge Patricia Goliath will today make a ruling on whether the authenticity of this evidence should be dealt with in a "trial within a trial"...