Microsoft, which won a ban last year on importing some phones made by a Google Inc subsidiary, filed a motion in a U.S. court on Friday asking the U.S. Bureau of Customs and Border Protection to enforce the measure.
The U.S. International Trade Commission, which hears a long list of high-tech patent complaints, said in May 2012 that Google's Motorola Mobility infringed a Microsoft patent for generating and synchronizing calendar items. It barred any infringing Motorola Mobility device from being imported into the United States.
All phones with Google's Android software are affected by the ban, Microsoft said.
That order was to have gone into effect 60 days after it was issued but, according to Microsoft's court filing, it still has not been enforced.
"CBP (Customs and Bureau Protection) has repeatedly allowed Motorola to evade that order based on secret presentations that CBP has refused to share with Microsoft," the complaint said.
A spokeswoman for U.S. Customs had no immediate comment. A spokesman for Google also had no immediate comment.
The filing is the latest salvo in an international smartphone patent war that has embroiled a half dozen companies in lawsuits filed in about a dozen countries.
The dispute is a sign that deciding which product infringes a patent is harder now that the world has gone high tech, and that Customs may not have the needed expertise to make that determination and perhaps should rely on the ITC, said Deanna Tanner Okun, a former ITC chairman who is a partner at Adduci, Mastriani & Schaumberg, LLP.
"Problems have increased. The system is outdated," she said. "They're using practices and procedures that are 20 years old."