"It is with regret that we terminate membership for both Maleina and Leilani as playing band members. We also terminate Talia and Latia as learner players, as well as Elizabeth's position on the executive committee."
The committee said its decision was "full and final", and asked for any band equipment or uniforms to be left at a police station.
The Herald understands the Grey family had been involved for several years with the band without incident until a discussion in February in the lead-up to a national competition led to a dispute.
That resulted in a complaint to police that Mr Grey assaulted the band's pipe major, Bryce Gilchrist.
The police said Mr Grey was warned about his behaviour but Mr Grey denies receiving a warning, although he admits neither party behaved as adults should.
He says his daughters are being unfairly punished.
Mr Gilchrist said the band had no issues with the behaviour of the girls, but by necessity, it meant having a relationship with the parents.