The British singer dated the Hollywood actress during his hey day with rock group Razorlight and they ended up living together in London.
However, Borrell admits the relationship was dealt a blow following a particularly rock 'n' roll moment at a wild house party.
When asked about rumours which suggested Dunst dumped him because he rode a Harley Davidson through her house, he tells Britain's Seven magazine, "The worst thing about you saying that is there was no Harley involved - it was a 1969 Triumph T100 Competition. And there's a big difference. It's a sixties British bike I was running around town as transport at the time, in London. We had a house in Islington. But yeah, I did ride it around the house - it was a party... There was a huge window, a crowded party, lots of people, and it was very inviting for a bit of brum (sic) through a sea of people. It's quite a good story - apart from the Harley aspect."