Australian metalcore band Polaris have confirmed the death of guitarist Ryan Siew at the age of 26.

Siew died on June 19, the band announced in a post on Instagram, in which they called the guitarist "our dear brother and bandmate," and "our best friend and artistic soulmate."

"He was kindhearted and clever, he was funny and brave and creative, and he was talented beyond all measure. He loved art, and beauty in all its forms. He loved great food in great company. He loved Harry Potter and psych-thrillers and crime documentaries," the post reads.

"He loved music, more diversely than you could ever imagine, and spoke its language in ways that only the rarest among us do. And most of all, he loved & adored his family & friends," it continues.

"He was also much admired and beloved by so many. Ryan, we will love and miss you for the rest of our days, and we will never fill the hole that you leave in all of our lives," the band added.

Polaris went on to ask that people respect Siew's family's desire for privacy, and also to give the band and their team space to grieve.

Polaris are preparing for the release of their latest album, "Fatalism," on September 1.

The band were on a promotional European tour, but last week announced that they would be canceling all outstanding tour dates "due to a serious personal crisis in our family."