Police on Friday issued summons to the actress and about 100 others who have purchased the poison from a factory based in Bangkok’s Lat Krabang district.
The cyanide was reported to be from the same batch as that of suspected serial killer Sararat "Am" Rangsiwuthaporn.
The actress said in an interview last week that she had bought a single vial of cyanide over the internet to kill monitor lizards in the canal near her home for fear they would harm her dogs. The actress claimed she has not yet used the cyanide.
Surachate said that investigators had found no evidence of the actress breaking any law. He added that the amount of cyanide she had purchased was small, but officials needed to question the reason for purchasing and from where, as required by law.
He added that cyanide is classified as a type-3 hazardous substance under the control of the Department of Industrial Works. A permit is required to import or be in possession of the chemical.
Surachate said police will coordinate with the department to check all importers and manufacturers of the chemical to ensure that they all have permits and use the substance strictly for the intended purposes.
Police are looking to crack down on importers who resell the hazardous substance to others without a permit, he added.