Tax on directors loan

I have been on PAYE for £600/month and the rest, £1400, my employer has been giving me as a directors loan.

I am not entirely informed how that is possible, all I know is that I signed a contract to be a 'partner' (although I never was) so we can sort this type of payment.

I am now leaving the company and am not too sure whether I need to pay tax on that loan, moreso if I owe money to the company? Total paid as loan is £13,400.