Police have urged the public to be vigilant after discovering a "large number of dog treats" scattered across a housing estate.
Officers from Gwent Police said on Saturday that the treats were discovered around an estate near Crosskeys.
They said the motive was "unclear" and advised dog owners in the area not to allow their pets to eat the treat as a precaution.
They said that other than a "strong fish smell" from the treats, there was no indication that they contained poison, but they said walkers should continue to be vigilant when walking their dogs.
There have been a number of suspicious incidents involving dogs in the South Wales area in recent months. In February WalesOnline reported on the terrifying level of dog thefts which has involved targeting dog walkers, cutting out microchips and led to huge numbers of dogs being recovered by the authorities.
Last month more than 20 dogs were recovered by police in the Ringland area of Newport. However, there is no indication that this incident has any link to dog thefts.
A Gwent Police spokesperson said: "We received a report of a suspicious item in Garden Suburbs, Pontywaun, near Crosskeys, on Friday May 21 at around 12.25pm after a member of the public found a number of dog treats.
"Anyone who sees anything suspicious is advised to report it to us on 101 or to call 999 in an emergency."
