The parents of a young British woman murdered in Japan have made a tearful public appeal in a bid to find her killer.Lindsay Hawker, 22, was found dead in a bathtub full of sand on an apartment balcony near Tokyo in March.Japanese police have launched a nationwide search for Tatsuya Ichihashi, who slipped away barefoot when officers arrived at the apartment to question him.Lindsay's father, William, said at a news conference in Tokyo: "If anybody is harbouring him, you must come forward, you must give this evil man up. He is a disgrace to society."Japanese police also announced a reward of £4,000 for significant information on the case.More than 100 police officers have been assigned to the Hawker case and British officials have said they are satisfied with Japanese efforts.Two British police officers arrived in Japan last week to liaise between the family and Japanese police.Japanese police have come under fire for their investigations into previous attacks on foreign women, including Briton Lucie Blackman, whose dismembered body was found buried in a cave near Tokyo in 2000.The Hawkers have launched a website (www.lindsayannhawker.com) to appeal for information and will appear on a crime programme on Japanese television to publicise the case on Saturday.The lack of leads on Ichihashi has led to speculation that he may have committed suicide, but Hawker's mother Julia said she had been told the inquiry is continuing on the assumption that he is still alive."I think it's a question on everybody's mind. They've got no evidence to suggest that he has. They are leading the inquiry fully in the expectation of apprehending him," she said.© Independent Television News Limited 2007. All rights reserved.