A senior NHS official faced calls to resign over his links to a scandal-hit hospital trust where mothers and babies died.
Mike Farrar, who heads the body representing NHS trusts, was in charge of North West Strategic Health Authority (NWSHA) at the time of the failings at Morecambe Bay.
The Parliamentary and Health Service Ombudsman (PHSO) confirmed it was investigating complaints against the NWSHA.
James Titcombe, whose nine-day-old son Joshua died at Furness General Hospital, said Mr Farrar should consider his position as chief executive of the NHS Confederation.
He told the Independent on Sunday:
There was a failure, in my opinion, of the NWSHA in its duty with midwifery supervision. That was a serious failure that is being investigated.
The whole role of the SHA has been highlighted as dysfunctional.
I think (Mr Farrar) should consider his position. He has always said the buck must stop with managers. But he has never taken responsibility for his role at the SHA.
Parents of a baby girl, who died at one-day-old, have said they are "sickened" they were not told of earlier failings at Furness Hospital.
The health watchdog has named the individuals accused of allegedly covering up its failure to investigate at a Cumbria maternity unit.
Cynthia Bower has been named as one of the individuals allegedly involved in the hospital deaths inquiry 'cover-up'.