“It brings me great sadness to tell you that Kris & I have separated,” the younger sister of pop star Kylie Minogue tweeted.
“We still care for each other and ask for privacy at this difficult time, in particular for our son Ethan who remains our number one priority.”
The former X Factor judge later posted: “Hi Tweet peeps. Needing to retreat for a
while. Thank you for your ever loving continued support.”
Minogue, 40, met Smith, now a model, on the party island Ibiza in 2008.
The couple, whose son Ethan arrived in July 2010, spent their time between London and Melbourne, where Minogue recently launched a fashion label and is a judge on Australia’s Got Talent.
Smith, 33, also commented on the break-up on Twitter.
“Dannii and I have a deep mutual love and respect for each other and although things have not worked out we have a gorgeous son together that we both love and implore everyone to respect our privacy at this challenging time,” he said.
Minogue was once briefly married to Australian actor Julian McMahon and had been engaged to Formula 1 driver Jacques Villeneuve.