Gwent Police said the six-year-old dog was registered and that a certificate of exemption had been issued in 2024, before a ban on the breed was introduced.
ACC Townsend warned the community over any speculation online, adding if anyone had information “on the dog involved – a male, black XL bully – and its previous behaviour, please contact us directly”.
“I understand that there is a lot of interest about this in our communities, but this is now a live criminal investigation,” she said.
“It is vital that people think about how their online commentary, in particular social media comments or posts, could impact the ongoing investigation and the criminal justice process.”