The industrial herbicide is used to kill insects from the roots of orange trees.
It was found wrapped around meat products that were left in one of the playgrounds in Nueva Andalucia.
It was just one of the substances picked up by lab experts at the local Health ministry.
The town hall said it has not been able to use this type of product ‘for a long time since its use was vetoed.’
The comment came after rumors surfaced that the substance the pets ingested is a pesticide that is still being used by the town hall to treat weeds.
The Policia Nacional and SEPRONA are continuing their investigation and seek to charge suspects with animal abuse, a criminal offence.
The deputy mayor of Nueva Andalucía said that three complaints have been filed for dog deaths and that the town hall has so far counted seven dogs and one cat as fatal victims.
The PSOE says there at least 14 dead dogs and two pets were intoxicated near the Mayor’s Office in Nueva Andalucía.
Detectives first found ‘toxic substances’ at San Pedro’s Eucalyptus Park, as well as Parque la Futura, in Marbella’s La Campana area, almost two weeks ago.
Police closed off both parks after poison was discovered by children’s swings and climbing frames.
Some dogs perished within minutes of coming into contact with the substance and even sniffing it caused death within an hour.
Since then, the Olive Press exclusively revealed that a British expat’s dog was killed in a similar fashion east of Marbella in Bello Horizonte.
The local government is expected to make a further statement on the case.