Two babies were given contaminated hospital feed linked to the death of one child and the serious illness of 14 others.

The feed was given to two children on the neonatal ward at Lister Hospital, in Stevenage, towards the end of last month. They have not shown any sign of illness but are being “actively monitored”.

Health authority Public Health England is currently investigating babies who have been fed batches of the intravenous liquid, called parenteral nutrition, made by London pharmaceutical company ITH Pharma.

Fifteen babies in six hospitals across England developed septicaemia after being infected with a bacterium, known as Bacillus cereus, shortly after receiving the feed. One of them died at London’s Guy’s and St Thomas’ Hospital on Tuesday.

A spokesman for the East and North Hertfordshire NHS Trust, which runs Lister Hospital, said: “When we were alerted that there was a problem with this solution, we acted immediately to ensure no more of it was used. Two babies had received nutrition from this batch.

“This was some days ago and neither has developed symptoms and are both well now. Indeed sufficient time has elapsed during which symptoms normally would be expected to have appeared.

“Having only be alerted to the problem late yesterday (Wednesday) afternoon, we’re now in the process of informing parents of babies in our neonatal unit.”