Joy Kirby, 46, of Heddon-on-the-Wall, Northumberland, and Wendy Easen, 50 of Gosforth, had claimed unfair dismissal after being sacked from Musgrave Primary School, Gateshead.
Following a row over a netball match the teachers were asked to speak to Jeff Redmayne, the school's owner. The tribunal in Newcastle upon Tyne was told that Mr Redmayne used a tape machine hidden in the handle of a briefcase to record the meeting.
He claimed the meeting was the culmination of a feud between the two teachers and their head, Pamela Wood. He said they had waged a campaign to discredit Mrs Wood by organising a netball club behind her back and then trying to blame her for not providing first aid.
Mr Redmayne had intended to prove, using the tape, that the teachers had changed their story between the original meeting with him in 1994 to a disciplinary hearing the following year.
But on Thursday the tribunal ruled that his claims had no substance. The chairman said: "Mr Redmayne decided the teachers were guilty of gross misconduct . . . He was not able to say what the collusion was about . . . no reasonable employer would have come to this decision."
Mrs Easen was awarded pounds 11,500 and Mrs Kirby pounds 12,500.Reuse content