Gabor frames in $\ell^2(\mathbf Z)$ and linear dependence

We prove that an overcomplete Gabor frame in $\ell^2(\mathbf Z)$ by a finitely supported sequence is always linearly dependent. This is a particular case of a general result about linear dependence versus independence for Gabor systems in $\ell^2(\mathbf Z)$ with modulation parameter $1/M$ and translation parameter $N$ for some $M,N\in \mathbf N,$ and generated by a finite sequence $g$ in $\ell^2(\mathbf Z)$ with $K$ nonzero entries.