Kylie Minogue's sister has revealed that she used "laughter medicine" to help the singer recover from breast cancer.

The pop star, 37, has been declared cancer-free and is back in the recording studio a year after being diagnosed.

Her sister Dannii says Kylie supplemented chemotherapy with old-fashioned fun to raise her spirits.

"We'd listen to music, dance and watch funny films," says Dannii, 34. "We loved to do what we call 'daggy dancing' - just really stupid dancing to anything I had on my iPod, anything happy and fun.

"This guy called Paul Anka has an album of cover songs but because they're so different and swing music, we played Name That Tune. Kylie's so good at it."

But behind the laughter Dannii, who is about to release her fifth album, confesses she found it hard to keep a brave face.

"We were told from the beginning Kylie's cancer could be treated and this would be the outcome but until you actually hear it, only then can you go, 'I couldn't breathe for a year but now I can,'" she tells Cosmopolitan magazine.

Dannii adds: "One thing that would be a complete achievement would be to see her finishing her Australian tour. That would be amazing. That would be something to mark that it's all in the past."

The full interview appears in the June issue of Cosmopolitan magazine, out on Monday.