A baby has been given breast milk from the wrong mother in a Queensland hospital, prompting a nervous wait for his family as he undergoes disease testing.

A three-week-old baby is undergoing tests for HIV after being given breast milk from the wrong mother in a southeast Queensland hospital.

The Metro North Hospital and Health Service says it is urgently investigating the circumstances surrounding the incident, which occurred at Caboolture Hospital on Thursday.

It says it has also apologised “unreservedly” to the baby’s parents and the donor mother.

“Medical advice, provided to the families, is because of the good health of those involved there is negligible risk of health impacts to the baby as a result of this incident,” a spokesman told AAP.

“However as a precaution, to give peace of mind and certainty to the families involved, blood and milk samples have been taken for comprehensive testing.”

Results are expected to be available within a week, with a routine confirmation test to occur again in 12 weeks.

The mix-up has caused a nervous wait for the baby’s family.

The baby’s grandmother, who only identified herself as Peggy, rang Brisbane talkback radio in distress on Friday morning saying her grandson was being tested for HIV, as well as Hepatitis A, B and C.

“My son and daughter-in-law are beside themselves,” the upset grandmother told 4BC.

“We’re on tenterhooks and to have something like that happen at a hospital, who’s not doing their job?”

The grandmother said a nurse gave a bottle to her daughter-in-law only to return five minutes later and say it was the wrong one.

The health service spokesman said any issues identified by a formal investigation would be addressed to prevent a recurrence.

Staff involved in the incident had been counselled about the importance of following all protocols in relation to expressed breast milk, he said.