She didn’t expect to be confronted by police in the schoolyard when the initiative was axed nine months later.

“It was deplorable,” she said.

Dramatic scenes unfolded at Kingston Heath Primary School in Cheltenham on Friday after Montessori Australia Foundation called in the police to prevent families taking off with classroom materials – including wooden beads, counting blocks and shelving – on the final day of the short-lived program.

This followed 17 families demanding that the organisation refund them the $1700 they had paid for these materials. They paid a further $950 in registration and program fees.

Mrs Wood said police helped parents negotiate with the school so they could enter the classroom, collect their children and pack up their schoolwork.

"It's been incredibly disruptive," she said. "This should have been a really grounding year for children in prep."

The roll-out of the program has been plagued with issues and raises questions about the Education Department's oversight of third-party programs in state schools.

Families have been left in limbo following its termination.

Mrs Wood's son Hugo is now being home-schooled and will repeat prep at another state school next year.

In December, Kingston Heath partnered with Montessori Australia Foundation to deliver the child-centred education method, which involves mixed-age classrooms, greater student choice in activities and the use of natural materials, such as wood.

It followed a long-running campaign from families who wanted their children to transition from Montessori kindergartens into a school stream.

But in May, just months after the inaugural class of Montessori preps and grade 1s started the program, the school council unanimously voted to scrap it.

The school then realised that its Montessori teacher was employed on the wrong visa.

“It has come to our attention today that the working visa of our Montessori teacher ... did not stipulate that she had the ability to teach and is therefore in breach of federal immigration laws," acting principal Megan Dell wrote to parents last week.

"We have been advised by the Department of Education legal department that [the teacher] cannot continue teaching at Kingston Heath Primary School, effective immediately."

Parents blame the saga on a lack of leadership at the school, which has had five principals in two years.

Montessori Australia Foundation president Christine Harrison said police were called after the organisation became aware that parents intended to remove $30,000 worth of furnishings and materials from the classroom.

She said they planned to store them to "use as bargaining power in their negotiations to obtain fee refunds".

Ms Harrison said she had the "greatest empathy" for all families involved in the situation.

"Our focus as Montessorians is always with the best outcomes for children and we wish all the students and families the best possible outcomes under these difficult circumstances."

She said the organisation was seeking advice about the handling of all fee refunds.

An Education Department spokesman said the school acknowledged that the situation had distressed parents and was working to keep them informed and supported.

"Decisions on refunding fees paid to Montessori Australia for tuition and equipment is a matter for Montessori Australia," he said.

"The department will be contacting Montessori directly to raise parents’ concerns and come to a solution that works for all parties."

Despite the drama, parents said they were happy with the short-lived program and spoke highly of the teacher.

Secil Sander, who moved from Croydon to Cheltenham so her son could enrol in the Montessori stream, said the program had been used to boost enrolments and parents felt used.

Her son will attend another local state school for two weeks before recommencing prep at the independent Melbourne Montessori School in Brighton East.

"It's a big systematic failure," she said. "It's people's lives they are playing with."