Dannii tweeted this morning, "It brings me great sadness to tell you that Kris & I have separated. We still care for each other & ask for privacy at this difficult time, in particular for our son Ethan who remains our number one priority."
Minutes later she added, "Hi Tweet peeps. Needing to retreat for a while. Thank you for your ever loving continued support."
The couple, who have a 21-month-old son, Ethan, are rumoured to be living apart after having ended their relationship two weeks ago.
Kris recently tweeted this cryptic message, "It's nice to be important, but it's more important to be nice... not really sure what my job is anymore... but I do know I love my boy more than life..."
Dannii and Kris were reported to have split in May last year after a series of cryptic break-up tweets, but they later issued a statement assuring fans they were still together.