Apparently he has reason to believe that the Trump empire was a money laundering enterprise. More particularly the new information pertains to the role of the Russian mobster Felix Sater played in advising the Trump campaign and that was revealed in an interview in Moscow a week after the election by Sater. The new information shows that Sater and Trump lawyer Michael Cohen was involved in a scheme to provide sanctions relief to Russia through a wild scheme proposed by a Ukrainian.
This is the type of thing the AG would know from his work in unsealing tax fraud allegations against Bayrock ,one of the investors in Trump Soho.
In fact I never knew this that the case to unseal record on Felix Sater went to the Supereme Court and had been opposed by the Federal government because of Sater's role as an FBI informant.
The whole sordid history of Sater and Trump did not end and in fact grew more intense during the campaign.