St Kilda midfielder Luke Dunstan has exercised his free agency rights and joined Melbourne.

Dunstan will join the Demons as an unrestricted free agent after not being offered a new deal by the Saints for the 2022 season.

The 26-year-old has played 116 games in the red, white and black after first making his debut with St Kilda in 2014.

Dunstan was limited to just the 12 appearances in 2021, however was able to poll 11 Brownlow votes for his efforts, ranking second at the club behind midfielder Jack Steele.

The acquisition will see Dunstan join an elite midfield group at Melbourne, who bid farewell to club great Nathan Jones (retired) and Aaron Vandenberg (seeking opportunities elsewhere) in the days following their drought-breaking flag win.

Dunstan would add great depth to the Demons' engine room, which boasts the likes of Christian PetraccaClayton OliverJack Viney and Angus Brayshaw.

Compensation for the Saints is unknown and will depend on the details of Dunstan's contract with the Demons, which is believed to be a two-year deal.