Investigations into an outbreak of E.coli affecting two children have shown that the type of infection confimed in the patients matches samples at a Brecon petting farm.
Both children had visited Cantref Adventure Farm in the days before they became unwell, and both are recovering at home.
Three other people, who are family members of the infected children, have also tested positive for the same type of E.coli O157.
The farm was advised to continue to stop direct contact between animals and members of the public while the exact source of infection is investigated.
Anyone who has visited the farm since the beginning of August has symptoms, they should still contact their GP as soon as possible.
The infection can pass from person to person and so it is important that anyone who is ill should observe strict personal hygiene to avoid spreading the infection.
Anyone who is unwell with E.coli O157 should stay away from school, nursery or work while they have symptoms and until they are advised that they are well enough to return.
E.coli O157 is a very serious infection that causes very severe diarrhoea, sometimes with blood in it, abdominal cramps and fever. In children, it can cause kidney failure that can prove fatal.
Anyone who has concerns about their health should contact their GP or NHS Direct Wales on 0845 46 47.
More top news
John Atkinson has resigned - but insists that his decision is about workload and nothing to do with recent problems within the Welsh party.
Amelia's mum Sarah Jones described how her dad was "panicking" when he told her the baby was "not breathing".
Former rugby star Ian Gough has won an assault appeal against former Miss Wales and ex-girlfriend Sophia Cahill.