'I should've dealt with things differently' says sacked specialist who worked with vulnerable women

An eminent psychologist has been sacked, arrested and could be struck off the professional register after a female patient revealed that they had had a long-term sexual relationship.

Keith Broadbent, 59, a clinical psychologist with more than 25 years' experience, started a relationship with patient A, aged 30, around six months after he became her therapist at a pioneering clinic that treats mostly female patients with borderline personality disorder. He is said to have bought her expensive gifts, including a laptop, and given her money, before she moved into his north London home.

Mr Broadbent was dismissed by Camden and Islington NHS Foundation Trust for gross professional misconduct in February – a month after the woman revealed the relationship to a community psychiatric nurse.

The trust has been criticised by sources close to the case for failing to properly investigate whether Mr Broadbent, who treated hundreds of patients in his 22 years at the trust, has conducted improper relationships with any other patient. He last night admitted to an earlier relationship with a former patient but gave no other details.

The trust is also criticised for failing to protect the identity and whereabouts of patient A since her disclosure.

Mr Broadbent was arrested at his home at 7am last Tuesday and questioned about allegations of harassment involving hundreds of texts, emails and phone calls to patient A since she moved out in January. Bailed until the end of next month, he denies the allegations, claiming the relationship was still ongoing at the time.

Patient A's mental health has deteriorated and she has spent several months in a crisis centre suffering from depression. Mr Broadbent was suspended from the psychology register by the regulator, the Health Professions Council, in February as an interim measure while it investigates the allegations.

Just over 16,000 practitioner psychologists are currently registered by the HPC, which started regulating the profession in April 2009. But only specialists, such as clinical, forensic and educational psychologists, are required by law to register. Anyone can set up a clinic as a "psychologist" without being subject to the professional code of conduct. The British Psychological Society has 45,000 members, which means two-thirds are unregulated.

Mr Broadbent was instrumental in setting up the Oscar Hill Service which uses dialectical behaviour therapy to treat vulnerable patients with complex emotional and behavioural problems such as recurrent suicide attempts, self-harm, binge eating, paranoid thoughts and drug abuse. Patients treated in the three-year programme are often highly traumatised as the majority have suffered childhood abuse and neglect.

The sexual relationship started after patient A told Mr Broadbent she had developed feelings for him in an email last April, the interim orders review hearing was told last week. He replied in an email that he "felt the same way" and he wanted to "kiss and hold her".

The panel heard how the relationship quickly developed and the two would "kiss and cuddle, and talk about dinner" during one-to-one therapy sessions. But within months patient A was struggling with the "lies and secrecy" and felt that "the relationship was wrong and that Mr Broadbent had violated her trust", the hearing was told.

After telling him she had disclosed the relationship to her nurse, patient A claims in a statement that Mr Broadbent said: "You have not left me any wriggle room. I will be crucified."

The HPC case investigator told the panel that there was a "further issue of a second patient with whom Mr Broadbent may have broken professional boundaries", but the trust was not investigating because he had been sacked.

He has also admitted giving patients financial help throughout his career, the hearing was told. He told The IoS he had given patient A large amounts of money, including £1,500 in June, supposedly to pay for a science course.

The psychologist did not attend the hearing but wrote a letter admitting the relationship. The interim suspension order was continued in order to "protect the public"; it must be reviewed again in three months.

Last night he told The IoS: "I just became deluded. I thought that I could save this patient from the circumstances she was in. I'd been giving her money before the relationship started, so I was already breaking the rules; it was sort of like an incremental drip... She has a background of extreme vulnerability... we had genuine feelings for each other but she found the whole thing very difficult... She has a history of picking up men... I am not trying to mitigate at all, but there was a whole range of her behaviours that I should have dealt with differently."

A spokesman for Camden and Islington NHS Foundation Trust said: "The trust is co-operating fully with the HPC, but will not make any further statement until the case is concluded."