Mid Staffordshire NHS Trust has been forced to apologise after a baby had a dummy taped to its face while its care.
The Trust, which is already is at the centre of a public inquiry into serious failings of care, said that a member of staff has been suspended and that police are investigating the incident.
The trust said the baby was unharmed in the incident.
Colin Ovington, director of nursing and midwifery at the trust, said: "We have a zero tolerance approach to poor patient care and we take immediate, appropriate action as soon as we know about any potential serious incidents which happen in our hospitals.
"The incident is under investigation by the police and so we are unable to give any more information at the moment.
"We cannot emphasise strongly enough that this incident is exceptional and apologise again to the family. We want other hospitals to learn from this incident so that we can be sure that it does not happen to any other baby."
A spokesman for Staffordshire Police said: "The baby boy, who was four months old at the time, was not harmed as a result.
"We are liaising closely with his family and the NHS Trust concerning the matter."
The report from the public inquiry into failings at the trust will be published on February 6.
It is understood the inquiry chairman Robert Francis QC will recommend wide-ranging reforms of the NHS.
The £11 million review of what went wrong at Stafford Hospital between January 2005 and March 2009 will suggest hospitals that cover up mistakes by doctors and poor treatment of patients should face fines and possible closure, it has been reported.
A separate highly-critical report by the Healthcare Commission in 2009 revealed a catalogue of failings at the trust and said "appalling standards" had put patients at risk.
Between 400 and 1,200 more people died than would have been expected in a three-year period from 2005 to 2008, the commission said.
In February 2010, an independent inquiry into events at the trust found it had "routinely neglected patients".
A recent report, conducted by a team of independent experts on behalf of regulator Monitor, concluded that Mid Staffs is "financially and clinically unsustainable".
It recently emerged that the trust has paid out more than £1 million in compensation to 120 victims of abuse or their families.