Ok so I used to listen this song at the clubs all the time in 2000-2001.
Brazilian song by a girl, very sensual.
It was a club song with brazilian rythm. The girl sung in portuguese.
It had this: na na na na naaaaaa na na na naa and then the lyrics. 3-4 loops. The 'na na' here is exactly as I write it, 4 short ones, one long, 3 shorts then another longer one (not as much as the first one) and this last naa is going down.