Sir David Nicholson has told MPs he regrets not meeting with the campaign group 'Cure the NHS' when the failings at Stafford Hospital came to light.
He told the Health Select Committee he instead dealt with them through intermediaries and "that was wrong".
Cure the NHS campaigned for a public inquiry into the failings of the Mid Staffordshire Hospital.
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The 21-year-old, who was arrested on Sunday, also allegedly injured two other people in the attack in the German city of Reutlingen.
She was going to the aid of a family member who got out of the car in the middle of the park and was dragged away by a different tiger.
The man, who was in his 30s, has not been identified, while several other people are believed to have suffered serious injuries.