Praminder Mankoo, 47, even asked his victims to moan as he massaged their scalps and then dropped his hands to grope them, it was said.

At least eight women, all suffering from hair problems and who had booked sessions at his specialist trichology surgery, were sexually assaulted during their treatment, the jury heard.

In a previous incident for which he was cautioned, he held a woman captive for a number of hours after stripping naked and asking her to perform a sex act on him.

Oxford Crown Court heard that the specialist faces 11 similar charges relating to eight other women in alleged sex attacks between November 2002 and September last year.

Over the five-year period he is accused of groping his female customers and using "inappropriate" language, as well as encouraging them to moan as he massaged them.

Prosecutor Kate Mallison runs a business called Hairology, in the Oxfordshire town of Thame, catering for people with hair or scalp disorders.

She said: "The people who feature in the indictment have one thing in common; it is not that they are all patients but that they all had a massage from the defendant and during the course of that massage they have found that the defendant has either been touching their breasts or touching near their breasts and/or using language that is sexual."

His earlier victim from the caution in 1998 told the court how she went for three sessions with him during which he asked her to wear sexy underwear and became increasingly bold in his advances.

In the final session he dropped his trousers and asked her "50 times" to carry out a sex act on him over several hours until he finally gave up and let her leave.

Mankoo, of The Nap, Oakley, near Oxford, denies two counts of indecent assault and nine counts of sexual assault.

The trial continues.