The Daily Mail said Saturday the incident occurred at Bassetlaw Hospital in the British town of Worksop when maternity staff members accidentally mixed up two newborns and delivered them to the wrong mothers.

While the mistake was discovered within hours, one of the babies had been fed and is now facing tests after ingesting milk from the wrong woman. Medical officials are concerned the milk may have been contaminated.

The director of nursing for the hospital said the Healthcare Commission had given the hospital's maternity unit a perfect rating in a recent report.

"We are one of only 38 best performing maternity units across the country," director Hilary Bond told the Daily Mail.

"There are areas where we know we can do better and we will use this independent review by the Healthcare Commission as a starting point."