I have a dual flush toilet.When the toilet has refilled there is a slight leak into the toilet bowl.After a while the tank has to refill.The leak continues and the refill once again comes in.It's a non stop process.
Sounds like the syphon is leaking. Have a look and see if you can remove the syphon from the cistern. I know on mine its a simple twist to remove it. You'll need to turn off the water feed and flush it to remove most of the water first.
Have a look at the condition of the syphon rubber valve and make sure its not damaged or being blocked by a lump of something or another.
If thats not the case then it might be that the part of the syphon that is screwed to the bottom of the cistern is leaking and needs re-sealing.
Dual flush system and a leak into bowl sounds like a modern loo where the cistern overflow is into the bowl rather than through a pipe into the wall.
If so then the problem is simple as is the cure. The float is set too high so that it is not shutting the water off and all that is happening is the level continues to rise until the overflow kicks in. Thats the dribble into the pan.
Take the lid off. On the float you'll see a screw adjuster. Normally anticlockwise sends it downwards. You need to turn the screw so that the float goes down and when the float shuts off the water supply the level is about 1" below the overflow outlet.
Problem solved. Trial and error a little bit but shoud take you less than 5 minutes.