The news comes just months after he left Saatchi & Saatchi under a cloud, having said in a media interview that the "fucking debate" about agencyland's openness to women occupying senior positions was "over".
While he later said he had been taken out of context, his comments were widely criticised, with Ketchum London boss Denise Kaufmann admitting she was "horrified" in an article for PRWeek.
Roberts resigned from his role soon after.
Laura Woods, CEO of Beattie Group, told PRWeek that the scandal was "not something that concerned us" when asked whether the issue was talked about in discussions with Roberts, who she said had known Beattie founder Gordon Beattie for a number of years.
However, the appointment has been criticised by some in the industry.
"It [the circumstances in which Roberts left his previous job] was irrelevant to us in all honesty," she said, going on to describe Roberts as "one of the most inspirational and brilliant creative brains in the world" and a "global leader".
Woods also said that Beattie's workforce was 80 per cent female, and that the leadership was predominantly female. "I think that makes our position very clear," she said. "We’re a meritocratic business, and so what matters is if you’re good enough to do the job".
On the group's international expansion plans, Woods said the company would be looking at expanding to other English-speaking markets. "We’ll go where there is growth, we don’t have any definite plans on geographies yet," she said.
The firm opened in Toronto last year, with the plan to open three further offices in the country in time. "We’re still getting that off the ground," said Woods of the company's first foreign foray.
High-profile clients of the firm have included fashion brand La Redoute, supermarket Iceland and glasses retailer Specsavers.