Barker headed the European operations for medical communications agencies Apothecom and Apothecom ScopeMedical, which form The APO Group.
Barker, who started in the role last spring, is understood to have left the company at the end of last month after resigning.
The APO Group declined to comment on the news.
Huntsworth Health, Huntsworth’s second biggest division, saw revenues grow by 7.1 per cent to £57.1m in the year ended December 2013.
