Results on edge turbulence during inter-ELM periods in MAST are presented. It is shown through combined measurements based on fast camera images and reciprocating Langmuir probes that filamentary structures influence the transport during these periods. A comparison of the Dα light emission amplitudes reveals that inter-ELM filaments are the lowest fluctuations in the MAST SOL relative to L-mode and ELM filaments. Physical properties such as size, density and mode numbers have also been characterised, along with measurements of the spatio-temporal evolution: Inter-ELM filaments are found to rotate in the vicinity of the LCFS, and propagate radially outwards. Motion of these filaments is found to depend strongly on plasma density such that with increasing density, there is an enhancement of the radial transport which is clearly manifested by an increased number of filaments which leave the edge and travel faster into the SOL. With the aid of camera images, it is shown that intermittent fluctuations in ion saturation current signals correspond to inter-ELM filaments passing the probe. Measured radial e-folding lengths indicate higher fall-offs at higher densities. Similar trends are also obtained in Monte-Carlo simulations of a filament propagating radially and losing particles on ion parallel loss timescales. Finally, a discussion is presented on how the radial velocity and Isat measurements have been used to test the predictions made by different models. The scalings observed in the data are at least a factor of 2 smaller than the models. In fact, the scalings have been found to vary as a function of distance in the SOL - a feature which is not captured in either model.