The lead Russian investigator looking into the hijacking of the Arctic Sea, is considering the possibility it was carrying more than just timber, according to the Interfax news agency.

The reported comment by Investigative Committee chief Alexander Bastrykin that “we do not rule out the possibility that they might have been carrying not only timber” is the first suggestion by a Russian official that the Arctic Sea could have been carrying a sensitive cargo.

The ship, which was carrying 6,700m³ of timber from Finland, disappeared on July 29. A massive hunt was conducted and Finnish authorities later reported a ransom demand before the Arctic Sea was found by the Russian navy off Cape Verde on August 16. A number of those on board were arrested.