"My decision to return home was not an easy one. But I simply miss my home and the people close to me too much," he wrote.

"I also have a burning desire to be a teacher and I want to start that stage of my life as soon as possible.

"I am also looking forward to playing Gaelic football again. I strongly believe my best moments of my sporting life are ahead of me and at this stage and I want to show them on the GAA stage."

With James McCartan recently installed as the new Down senior football manager, Clarke will be hoping to work his way into McCartan's plans for the 2010 campaign.

The push for senior selection will begin back at his local club, An Riocht, with whom he starred before his departure to Australia.

Clarke, who turns 22 in November, also played in two McRory Cup finals for St Louis, Kilkeel and won an All-Ireland minor title with Down in 2005.

Commenting on his Irish recruit's decision to quit, Collingwood chief of football Geoff Walsh said: "We sincerely thank Marty for his contribution and commitment to the Collingwood Football Club over the past three seasons.

"He's an outstanding talent who is very highly regarded by his peers and everyone at the club, and he will be missed.

"I'm sure Marty will be successful in his future endeavours, and on behalf of everyone at the club, I would like to wish him the very best back in Ireland."

Clarke is the second young Irish footballer to decide to return home from Australia in recent weeks.

Carlow's Brendan Murphy also ended his two-year, injury-interrupted spell with the Sydney Swans and is likely to feature for Luke Dempsey's Carlow side next season.