WA man re-sentenced over double murder

A man who murdered the mother of his two young children and his best friend in a methylamphetamine-fuelled rage in Perth has had his minimum jail term increased to 27 years.

Nikol Stoeski pleaded guilty to killing Vanesa Marija Farcich, 31, and Saso Filkovski, 37, in separate Girrawheen houses in May 2013.

Stoeski was originally sentenced to life in prison with a minimum of 21 years, but on Tuesday, the West Australian Court of Appeal agreed with prosecutors that it was manifestly inadequate and re-sentenced him.

In his judgment, Justice Michael Buss described the murders as "brutal, sustained and unprovoked".

Stoeski was under the delusional belief that his partner had been unfaithful and that his friend had spread rumours and was conspiring against him.

Ms Farcich died from asphyxiation and was left bound with duct tape in her bedroom with "666" written on her forehead.

Mr Filkovski, who had been friends with Stoeski for 27 years, was stabbed in the neck with a fishing knife and was bashed with a car part.