LONDON (REUTERS) - The psychiatrist brother of Britain's finance minister George Osborne was struck off the British medical register on Thursday for having an affair with a patient and threatening her to keep quiet about it, a disciplinary panel said.

Adam Osborne, who qualified as a doctor in 2004, was ruled unfit to practice over his relationship with the patient, who suffered from depression, anxiety, and other mental health issues, the Medical Practitioners Tribunal Service (MPTS) said.

"The tribunal has determined that Dr Osborne's abuse of his professional position, which included sexual misconduct, with a vulnerable patient he was treating for mental health issues, is fundamentally incompatible with continued registration as a medical practitioner," the MPTS said in its ruling.

Osborne, who was married at the time, began treating the woman, referred to as Patient A, on a private basis between February 2011 and late 2014.

He admitted that during that time he had a two-year inappropriate sexual and emotional relationship with her.

After he ended the affair, the woman took an overdose and had to be rushed to hospital.

The tribunal heard Osborne had sent e-mails telling her to withdraw her complaint and making threats against her and her family if she did not.

"If I get into trouble for this, then I will never forgive you for this and I will make sure you pay," one e-mail said.

In a statement, Osborne said he was saddened his behaviour had hurt many people.

"It was never my intention to hurt anyone, although I can now clearly see that my irresponsible behaviour has led to a great deal of distress to the people that I care about, in particular my family and the patient in question," he said.