could be one of three things
1, aftermarket large sump
2, the last time it was serviced it was over filled
3, you have leaking injector and its filling your sump with fuel
I would suggest you change the oil, keep an eye on it and after 5000kms drain it and take a sample, sample kits are available from most oil companys or oil analyisis companys. The test will tell you alot about what is happening in your engine, they cost around $30
ASHLY