Lockhart's house

[Hannah]

No: HPFGUIDX 117754


I was just wondering, does anyone know what house Gilderoy Lockhart 
was in?  The comments he makes in CoS before the first Quidditch 
match suggest he favours Gryffindor.  But surely he wouldn't have 
been in Gryffindor, being an utter coward.  Ravenclaw?  Not clever 
enough.  Hufflepuff?  Not loyal or hardworking.  I'd have him down 
as the perfect Slytherin - ruthlessly determined to be famous, and 
not afraid to use any means (including destroying the minds of 
heroic witches and wizards without any qualms) in order to get there.

Has this been discussed before?  Is there anything in canon/ JKR 
interviews that I've missed to give us a clue?  

Hannah