Washing machine wont complete drainage at end of wash cycle

I have a 4 yo F&P smartdrive (excellence) 6.5kg washing machine that has just started to stop draining at the end of the wash cycle. The maching notified me of the initial problem by beeping at me each second, no lights were flashing on the control panel though. Soo, I powered off and on, gave it another try, no luck. Emptied the clothes and water out of the bowl, took the centre agitator out, couldn't see anything obviously blocking anything, checked the drainage hose, doesn't appear to be blocked in any way. Left machine off overnight and tried again the next day, initally it completed the drainage of water from the previous night, so I attempted a short wash from the begining of the cycle only to have it stop again mid drainage at the end of the wash cycle. It appears to me as if the machine is trying to drain (as can hear it trying to work) but is blocked somewhere, don't know where to start investigating. Any suggestions??? Thanks :)