The radiologist accused of handing out dangerous drugs to late philanthropist Anita Chan Lai-ling wept in court yesterday when recounting her close relationship with her "sworn mother".
Yau Yat-yin, 55, told Eastern Court that not only was Anita Chan her patient and friend, "[she was] also someone very dear to me".
She then burst into tears.
Yau was originally charged with giving out dangerous drugs to an unauthorised and unlicensed person. But on Thursday, the prosecutors amended the charge to "supplying dangerous drugs", leaving out the latter part which specifies the receivers' legal authority to handle drugs.
Yesterday, Yau said she and Chan started referring to each other as sworn mother and daughter in 2000 to 2001.
After that, Yau would often visit Chan's home for dinner, and, while there, give her basic medical check-ups at Chan's request.
These included checking Chan's pulse and blood pressure.
The radiologist said she took Chan's medical inquiries seriously. "When someone asks you a medical question, you can't just say yes without really considering it," she added.
Responding to defence barrister Giles Surman, Yau agreed she had played a big part in treating the medical problems which Chan suffered in 2002.
Chan had severe back pain after a fall in the United States, where she received breast cancer treatment from 1998 to 1999.
After meeting Chan, the radiologist said she ran tests - including magnetic resonance imaging scans and computer tomography - to help Chan spot the source of the pain while monitoring potential relapses.
Yau also sought second opinions from other physicians.
Magistrate So Wai-tak also heard that Yau was experienced in the use of psychoactive drugs, some of which she had prescribed to Chan.
For example, Yau used morphine to treat anxiety-stricken soldiers when she was serving in the Australian army in the 1980s.
Yau registered in Australia as a general practitioner in 1981, and once worked as a GP in the small mining town of Collinsville, in Queensland, Australia.
Registered in Hong Kong in 1992, Yau said she was Chan's family doctor.
The court earlier heard that Yau had prescribed Chan more than 5,900 antidepressant pills and two painkilling patches in the four years before her death from an overdose in 2007. The case continues on Monday.