The aide caught up in the Matt Hancock scandal was put forward to represent his department at meetings with Public Health England, it has been reported.
Gina Coladangelo, a non-executive director at the health department, regularly attended advisory board sessions of the body despite having no clinical expertise.
The revelation, first reported by the BBC, comes amid questions over Ms Coladangelo's appointment.
Labour has called for the release of all documents regarding her being given the job as non-executive director – a role which included scrutinising and holding Mr Hancock to account.
Ms Coladangelo and the health secretary both left their jobs at the Department of Health and Social Care after video evidence emerged that they were having an extramarital affair.
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The PHE advisory board exists to give advice on running of Public Health England and to give it advice on policy and standards.
Nigel Carter, chair of the Royal Society of Public Health, told BBC Radio 4's Today programme that Ms Coladangelo's presence at the board meetings in lieu of someone with clinical experience was a "great cause for concern".
"We would certainly expect a representative from the Department of Health and Social Care sitting on the PHE board to have that relevant health and clinical experience to bring to the discussions, which it seems in this place didn't happen," he said.
The Independent has contacted the Department of Health and Social Care for comment on this story.
