The scheme, on Higham Common Road, had ten votes for and ten against, leaving planning board chairman Coun Ken Richardson - who gave his support - with the final say last month.
However, confusion arose immediately after the deciding vote was cast as residents claimed a miscount had occurred with nine for and ten against, with four other councillors not responding when their names were called during the vote.
The approval enables access to the MU1 site, the borough’s largest parcel of land allocated in the local authority’s development blueprint for the next decade, which will yield up to 1,700 homes, dozens of business premises and a primary school from its giant 122-hectare plot.
Coun Peter Fielding, who represents the Dodworth ward, said: “Concerns were heightened the next day when not only did the broadcast fail to appear on the council’s website, but all previous planning board meetings also disappeared.
“The roundabout will provide the only access to the largest industrial development site in Barnsley and the developers propose to provide no protection for the residents against noise and pollution from the roundabout adjacent to their homes.
“I am pleased that so many members of the board heard and listened to those objections and voted against the application, but I am concerned about the confusion and lack of transparency in the aftermath of the meeting.
“Residents have raised concerns about whether the vote was counted correctly. Having carefully reviewed the footage of the meeting, I share those concerns.
“Locals deserve an explanation on why the vote seen in the footage does not match the result declared, and why attempts were made to prevent public access to the webcasts of the meeting shortly after this controversy came to light.”
The Chronicle can reveal the local authority’s monitoring officer probed the claims after allegations of maladministration were lodged.
Coun Alan Gardiner, cabinet spokesman for core services, added: “The vote was tied at ten to ten, meaning the deciding vote went to the chairperson.
“This has been reviewed by the council’s monitoring officer, who is responsible for investigating allegations of maladministration.
“There is no suggestion of any misconduct and this has already been communicated to Coun Fielding identifying exactly how each member cast their vote.”