A hospital worker has been suspended at the scandal-hit Mid-Staffordshire NHS Foundation Trust after a baby was found with a dummy taped to his face.
Staffordshire Police confirmed officers were investigating a complaint about a staff member at Stafford Hospital, and were liaising with the baby's family and the National Health Service trust.
The 4-month-old boy was unharmed in the incident, which happened this month.
The incident is a severe embarrassment to the trust, coming 10 days before the launch of the report of a public inquiry into poor standards of care that went undetected for years.
Up to 1200 more patients died than would have been expected over a three-year period, in 2005-08, in one of the worst NHS scandals.