A leading eye surgeon has admitted that he carried out medical trials without getting his patients' consent.
The GMC heard that patients were not aware of the 'trial'
Dr Deepak Chitkara, 46, from Liverpool, put "untested" lenses into patients' eyes for a study at a Salford clinic, the General Medical Council heard.
He later signed a contract with the manufacturer, the hearing was told.
Mr Chitkara, who was suspended from the Rosen Eye Clinic, now runs his own practice, Viewpoint Vision Services at Salford Quays. He denies misconduct.
The GMC Fitness to Practice Panel, sitting in Manchester, heard that the firm Lenstech were paying Dr Chitkara $4,330 (£2,370) a month, as a consultant director for his help in developing their Kellan lens.
He also received commission on sales.
It is alleged he put the new Kellan lens in one eye and a CrystaLens - a product made by a rival firm, into the other eye of patients, to conduct a trial, without telling them.
Although the Kellan lens was licensed it was new and had not been used as widely as the rival lens, the GMC heard.
Dr Chitkara admitted using the lenses without asking patients first.
Daffyd Enoch, for the GMC, asked the doctor whether he conducted the clinical trial for financial gain.
"My use of the lenses was not decided by financial incentive," Dr Chitkara said.
Mr Enoch said he could have given the "tried and tested" CrystaLens to patients - but instead gave them a new, untested lens.
"Without consulting patients you used the one that's not tried and tested."
Dr Chitkara presented the results of the trials to an conference of eye surgeons in San Diego.
It is alleged he presented "misleading" data aimed to persuade the specialists that the Kellan Lens were superior to the rival CrystaLens.
A representative from the CrystaLens makers asked for the data and for him to withdraw the presentation.
Asked why he refused, Dr Chitkara replied: "It would be detrimental to their firm.
"Because he knew I was a consultant to Lenstech and I would favour Lenstech."
"Well, you said it," Mr Enoch replied.
The hearing continues.