The ANC's provincial executive committee had only charged the councillors who voted in a motion of no confidence against Tlokwe mayor Maphetle Maphetle seven months after the date of the alleged misconduct, he said in a statement.
"This was in contravention of the ANC constitution which provides that charges must be instituted within three months.
"Based on this procedural irregularity, the councillors were found not guilty," Hanekom said.
In July, the 14 councillors were found guilty on four counts of misconduct by the ANC's North West provincial disciplinary committee and were expelled from the party.
The councillors were charged for participating in a motion of no confidence against Maphetle in November last year which resulted in the mayor being replaced by Democratic Alliance councillor Annette Combrink.
They were also charged for failing to endorse the appointment of the municipal manager in June this year.
Balance of probabilities
Hanekom said the disciplinary committee found the evidence brought forward by the councillors for not supporting Maphetle were "possibly true".
"With regard to the charges relating to the appointment of the municipal manager, the [committee], after evaluating the evidence, found that the version of the councillors was reasonably possibly true and that the provincial committee erred in its finding that the ANC proved the guilt of the councillors on a balance of probabilities.
"The councillors were also found not guilty on these charges," he said.
Maphetle was returned as mayor in February when he won by 31 votes to Combrink's 21.
In July, ANC factions in the municipality passed a second motion of no confidence in Maphetle.
He was again replaced by Combrink – the first DA mayor in the province.
Maphetle lodged an application in the North Gauteng High Court in Pretoria to nullify the council meeting at which he was unseated. The application was dismissed by the court. – Sapa