We haven't had this problem, but started potty training by letting our boy run around outside with no pants on and talking about "doing a wee" when he did one.  Then we encouraged him to go out on the deck to do a wee (had to put up with several accidents on the carpet until he got the hang of it).  He would then get a container of water from the paddling pool and pour it over his wee to clean up - good boy eh?   After a couple of weeks he just started using the potty inside of his own accord, for both 1s and 2s - although he sometimes prefers to pee on the deck .  I think that being allowed to pee outside and watch it and talk about it helped him learn about letting go without having a nappy on.  Now we just need to teach him about getting dressed and undressed - he has no clue or desire to do that himself yet, and will just wet his undies/pants if he's wearing them but no nappy .

Sorry, that was a long winded suggestion!