The Templeton family, near Riverton, have a restored 105-year-old working flax mill and museum on their 404ha dairy farm, at Otaitai Bush, on the outskirts of Riverton.
Janice Templeton, who deals with the flax fibre orders, said they had recently sold fibre to Cricket Hop Productions New Zealand.
The Otago Daily Times has reported the company has completed filming what is believed to be a remake of the Disney animated movie, Mulan, in the McKenzie country.
The Templetons had also supplied fibre to two television companies, for the New Zealand movie The Dead Lands and the film depiction of author Eleanor Catton's The Luminaries in the past couple of years.
Mrs Templeton said they had also supplied fibre to a company involved in the production of Lord of the Rings.
The fibre produced from the flax is too coarse to be used as fabric, although several artists have bought the fibre to use in their work.
''We have one lady who makes beautiful wall hangings out of it,'' Mrs Templeton said.
''She has been asked to make commissions from all over the world. The last time I talked to her she had a commission from Germany.''
She said she had received inquiries from the University of Auckland for a possible research project and had sent samples.
They have also sold fibre to other research organisations.
She was pleased to think the fibre was being used for ''something positive'' like research and the movies.
The mill was restored and turned into a working heritage museum in 2004 by volunteers led by Des Templeton.
About 70 mills operated in Southland at one time, but the Templeton mill is the only operational one left in the country.
The Templeton Flax Mill Heritage Trust now runs and operates, it with Mrs Templeton's son Vaughan as its chairman.
He, brother Kelvin, Vaughan's sons Luke and Peter, and trust members Stephen Logie and Howard Robertson, both of Wallacetown, are all involved with cutting harakeke flax that grows on the property, and the mill operation.
The fibre was largely used to make rope.
The mill, which is part of the Riverton Heritage Trail, is open to visitors, and the Templetons give talks about its operation and history as well as demonstrations by appointment.
The flax is slow-growing and takes about seven years before it is the right size to process at the mill. The family used the flax bushes as shelter for the sheep and cattle before the dairy conversion .
''The cows love it as they chew on the base and get nutrients out,'' Mrs Templeton said.
''We have an open day once a year and 300 to 400 people come to have a look.
''Our next open day will be on during the Southland Heritage Month, on March 31, next year.''
