A Masterton woman threw water over a Chinese tourist because she objected to the visitor speaking in her native tongue.

Belinda Sutherland was sitting on a train behind a 52-year-old woman, who was talking in Chinese with another Chinese passenger.

A court was told yesterday that Sutherland then muttered: "We speak English in this country", a comment which was heard by other passengers.

She got out of her seat not long afterwards and, holding a bottle of water, moved towards the two women who were still talking and laughing.

Sutherland, 25, then said to them: "If you don't shut up, I will pour water over your head."

The Featherston to Wellington train on October 12 was approaching Petone by this time and the two Chinese women continued to talk quietly.

Sutherland got our of her seat again and moving to the women, splashed water over them then bent forward, grabbed the victim and punched her once.

She was restrained by another passenger who also alerted the guard to what had happened, Police prosecutor Sergeant Garry Wilson told the court.

When police arrived she lied to them about her identity and about being on the train. Once at Wellington Police Station she told police her real identity but denied she had assaulted anyone.

Sutherland, who was found guilty of assault, will be sentenced on January 25.