Adobe premiere pro cuts first 5-6 seconds of clip

Hi all,

I have been using Premiere pro to edit videos for a little while now. However, I have just noticed that in some clips, the first five or so seconds have been cut out. Though when i go into the file outside of Premiere is has the full clip there. It's only when i import into my project that the beginnings of some of the clips have been cut. 

Also the videos im using have been shot on an old camcorder that have been converted to MP4 files through VLC.

Any tips or ideas would be greatly appreciated as the beginning of these clips are crucial to my video! 

Cheers