The National Secular Society has questioned why an NHS trust has hired a therapist who will specialise in reiki, a form of spiritual healing "widely regarded as a pseudoscientific fraud".

Last month Northern Devon Healthcare Trust advertised for a 'reiki complementary therapist' to work in cancer services in the town of Barnstaple.

The therapist will perform the work for seven and a half hours per week from January. The successful candidate will have duties on the trust's chemotherapy day unit, inpatient wards and health and wellbeing unit.

Practitioners claim reiki harnesses the power of 'universal energy' to promote wellbeing. It is not recognised by the NHS as a therapeutic treatment for cancer or any other condition.

Dr Antony Lempert of the NSS's Secular Medical Forum has written to the trust to ask it to explain its decision. He said there was "no reliable evidence that reiki benefits physical or psychological health".

He added that hiring a reiki practitioner could cause harm by offering patients "false hope".

"Patients facing a cancer diagnosis rely on the professionalism of the healthcare team and rely on evidence-based treatments. Embedding a reiki practitioner in the team in this way gives the practice an undeserved veneer of respectability, which may be confusing for some patients."

In a response to the NSS's letter the trust said the post was being funded by The Sam Buxton Sunflower Healing Trust (SBSHT), with the trust's support. SBSHT provides funds for complementary therapists in NHS hospitals across the country.

The Northern Devon trust said a similar model was embedded in 14 NHS trusts and hospices across the country.

It also acknowledged that there was "minimal scientific evidence based research to support reiki" but said there was "a wealth of feedback from patients and staff" where reiki practitioners were used.

According to one study, reiki and other forms of 'energy healing' were offered in 57 NHS hospitals between 2010 and 2014 – with almost all providing reiki to patients. Reiki was also offered in many other conventional UK healthcare settings.

Explaining his decision to write the letter, Dr Lempert said: "NHS trusts should base their decisions on evidence-based care for patients. The available evidence for 'spiritual healing' techniques is comparable to the placebo effect, despite the grandiose claims of its 'advanced' practitioners whose qualification asserts that they can send healing energy over long distances.

"Patients are at liberty to access all manner of alternative interventions outside the NHS. Hiring a reiki practitioner is likely to embolden those who wish to undermine the NHS's commitment to evidence-based decision making."

Please note: This story was updated on Friday 30 August in light of the trust's response to our letter. We initially questioned why Northern Devon Healthcare Trust was funding the treatment. In response the trust has told us it is being "fully funded by The Sam Buxton Sunflower Healing Trust, and supported by the Trust". Our story has been changed to reflect this.