“He then climbed on top of me and straddled me. He was breathing in my ear, making sexual, grunting noises. He had his hand resting on my upper thigh and I had a dress on. He was moving his hand up and down.”
She said that she placed her hands over her face “and waited for it to be over”.
Mr Kelvin was also alleged to have insisted on hugging new employees, as well as making women sit in his lap.
The executive chair of the company, David Bernstein, praised Mr Kelvin “for his tireless energy and vision.
“However, in light of the allegations made against him, Ray has decided that it is in the best interests of the company for him to resign so that the business can move forward under new leadership."
An independent investigation into the allegations, conducted by City law firm Herbert Smith Freehills, is currently under way.
