That piece of conjecture was included in Ozzie news broadcasts.
This was in the CDI-Russia weekly reprinted from Moscow Times if I am not mistaken. "Dagestani Kamikaze" was the term used, the claim is that there were 2 Dagestani/Chechen stowaways on the ship who detonated the explosion, and that this was corroborated by some Chehcen folks claiming responsibility.
To my knowledge there are three websites, one maintained by the Chehcen government, one by The Chehcen Times and one other, that might shed some more light on this. However I am going to test my theory that the side of my face is an effective replacement for a steam iron by working over the wrinkles on my pillowcase. Let me know though if you want the URLs, if so i will post them tomorrow. mcapri