Why did Dumbledore call for Winky?

[Richard Jones]

No: HPFGUIDX 125400



At the end of GOF, after the fake Mad-Eye Moody was caught but before 
the polyjuice portion had worn off and he changed back to Barty 
Crouch, Jr., Dumbledore had Winky brought from the kitchen.  How did 
he know that Winky would know anything about what was going on?  
There was no apparent reason to suspect that the Crouch family was 
involved.  So what did Dumbledore know and when did he know it?

Richard Jones