A patient dying of liver failure has been given a ray of hope after a relative emerged as a potential transplant donor, family members said yesterday. If the relative passes a series of biological and psychological tests, Ricky Cheng Kin-kwong will be able have the transplant as early as today, doctors said. But Cheng's wife, Emily Tsui Yee-wan, remained cautious. 'Nothing has been finalised yet,' she said. 'We do not know if the relative can really pass all the tests.' Professor Lo Chung-mau, head of liver transplants at Queen Mary Hospital, said the operation would be carried out early today if the donor measured up. The family of Cheng, 42, has been desperately seeking a donor since Saturday after his liver function dropped to 10 per cent of normal. Doctors told them that without a transplant, death within three months was a 90 per cent likelihood. Cheng, an optometrist, has been placed top of the waiting list for a liver from a dead donor, but it is rare to find a suitable and functional one from this source. His siblings are all unsuitable as the family has hereditary hepatitis B and the blood types of other relatives do not match. Crystal Ku Wing-yin, Cheng's niece, said some relatives had flown from Australia to see if they were suitable donors. Meanwhile, more than 40 strangers offered to help after an appeal by Tsui on Facebook which received wide media attention but no one was deemed suitable. Cheng, a hepatitis B carrier since he was young, needed drugs to control his condition. Two weeks ago, he experienced acute heartburn and was rushed to the Caritas Medical Centre in Sham Shui Po. He was prescribed drugs but the situation worsened, and he was transferred to Queen Mary Hospital. Doctors said Cheng's condition had become drug-resistant and that his kidney functions were deteriorating along with his liver. Ku said doctors recommended the transplant be done this week, as Cheng's condition could worsen at any time. They said any surgery would be futile if Cheng developed severe complications, such as pneumonia or bleeding in the brain. Liver donation is a major operation in which donors would receive a long-term 20cm scar and need four to five weeks to recover. There is also a five per cent chance of complications and 0.5 per cent chance of death. However, the donor's liver will grow back to its original size in about a month.