Fume/Petrol Issue

[pariAh]

Ok, Just driving around in my car, around a few round abouts and just driving normally and started to smell petrol... thought it was a one off continued to drive with this smell.. 2weeks later and its getting worse so i took to the local garage and they dont know whats a matter with it, its not anything with the exhaust and from the engine bay, its inside the car and in the boot..
after getting home i checked the seal underneath the back seats of the car( where the fuel comes through) and its prefectly dry!!
anyone have any ideas on what is the issue?..

maybe a fracture in the fuel pipe?
100% that it is petrol smell though, there isnt any exhaust fumes what so ever, and the fuel gauge isnt showing any changes
mostly happens after going round a roundabouts but im not really sure how it starts...

is this a common problem with corsa's 1.2 16 2000?

cheers for reading

[pariAh]

any ideas anyone?.. cheers