Dumbledore and Malfoy conversation. Is that a clue?

[rt11guru]

No: HPFGUIDX 135398

> JJ's response:
> DD seemed very pleased that Kreacher responded to Harry as his new 
> master.  Perhaps DD was pleased, not because the OOTP HQ would not be 
> turned over to Bellatrix or Narscissa, but because he had proof that 
> the strong magic keeping Regulus so well hidden that he was thought 
> to be dead was still working.



Guru says:

Don't you think it's likely that if DD were hiding Regulus from LV, at
somepoint Reggy might have said, "Hey DD, did I tell you about the
neat locket that I boosted from You-Know-Who's secret cave"?