Nortel Networks on Friday completed the sale of its 6,000 treasured patents and patent applications to the purpose-built Rockstar Bidco consortium consisting of Apple, EMC, Ericsson, Microsoft, RIM and Sony for a dazzling $4.5 billion.

Now all the buyers have to do is get to keep the prize that Google wanted.

As the IP was changing hands, the Wall Street Journal reported that the Justice Department was cranking up its unannounced investigation into whether the buyers could use the patents to "hobble" Android smartphones - and presumably by extension Android tablets.

Quoting people supposedly in the know, the paper says the Rockstar Six are being interrogated about their intentions to sue Android players. The DOJ is looking for collusion.

Others are apparently being asked to share their concerns.

As previously reported, the Justice Department, which cleared the bidders before the auction, could still impose conditions on the deal like it did with the Novell patents that Microsoft couldn't keep, while EMC was barred from taking Novell's virtualization IP, and Apple and Oracle had to pledge not to bare their teeth.

Rockstar has never publicly divulged what it means to do with the Nortel patents or how it might divide them since contributions to the winning bid varied, with Apple kicking in $2.4 billion, the lion's share.

The portfolio is said to touch nearly every aspect of telecommunications as well as Internet search and social networking , spanning wireless, wireless 4G, data networking, optical, voice, internet, service providers and semiconductors.

Google-Intel was only $100 million under Rockstar's winning bid and blanched.