Police have confirmed an investigation remains ongoing following reports that three Amey workers fell ill after drinking tea provided to them by a resident while they were felling trees in Sheffield.
The Star understands the contractors became ill after working in the Dore area in October and reported the issue to the police.
South Yorkshire Police confirmed it was investigating "reports of three alleged assaults on three workers who were felling trees in Sheffield".
A source, who did not want to be named, said: "I spoke to one worker who said he had a cup of tea during his shift, finished work but then became violently sick.
"He took the next day off work and then discovered his two colleagues had similar symptoms.
"The worker said they felt they had been given something because the symptoms were so similar and severe so they reported it to the police.
A South Yorkshire spokeswoman said: "South Yorkshire Police are investigating reports of three alleged assaults on three workers who were felling trees in Sheffield - this matter was reported during October 2017.
"Officers have carried out forensic tests and have spoken to a number of witnesses regarding this matter and enquiries are ongoing."
The workers' claims are the latest in a long-running battle between campaigners trying to save trees and workers trying to fell and replace them as part of the council's £2.2 billion Streets Ahead programme.
An Amey spokeswoman refused to comment on the incident.