Alan Walker has announced his resignation as chairman of the beleaguered staffing firm Healthcare Locums (HCL) together with Alasdair Liddel, who is stepping down from his position as Non-Executive Director, The Daily Telegraph newspaper reports.

HCL suspended Executive Vice-Chairman Kate Bleasdale and Finance Director Diane Jarvis in January 2011 after announcing "serious accounting irregularities".

Alan Walker will be replaced by Peter Sullivan, a former senior banker at Standard Chartered and Citibank. David Henderson, formerly Chairman of Kleinwort Benson is also joining the HCL board.

The Daily Telegraph understands that the investigation into accounting irregularities has been handed over to financial advisory and restructuring firm Zolfo Cooper. Findings are expected to be announced within weeks.

The arrival of two senior bankers on the HCL board and the presence of Zolfo Cooper are bound to lead to speculation that the company will be up for sale.