NEW YORK — The family that owns OxyContin maker Purdue Pharma used Swiss bank accounts to conceal the transfer of millions of dollars from the company to themselves, New York state's attorney general contends in court papers filed Friday.

New York — asking a judge to enforce subpoenas of companies, banks and advisers to Purdue and its owners, the Sackler family — said it has already documented $1 billion in transfers between those parties.

Those transactions include millions shifted from a Purdue parent company to former board member Mortimer D.A. Sackler, prosecutors said in the papers. Prosecutors say Sackler then redirected substantial amounts to shell companies that own family homes in Manhattan and the Hamptons.

The filing, made in a New York court, follows decisions by that state and others to reject a tentative settlement with Stamford, Connecticut-based Purdue, announced this week, arguing it does not do enough to make amends for the company's and family's alleged roles in flooding U.S. communities with prescription painkillers.

New York, Massachusetts and others contend that the Sacklers drained more than $4 billion from Purdue since 2007, moving much of it offshore to avoid future claims. In its filing Friday, New York told a state judge that the only way it can determine the full extent of those transfers is if all those it has subpoenaed are forced to provide documents detailing their interactions with the Sackler family.

"It is elementary, however, that how the Sacklers moved and tried to hide their money will be key evidence of the liability of all of the participants," a lawyer for the attorney general wrote the judge.

 The agreement with about half the states — including Ohio — and attorneys representing roughly 2,000 local governments would have Purdue file for a structured bankruptcy and pay as much as $12 billion over time, with about $3 billion coming from the Sackler family. That number involves future profits and the value of drugs currently in development.

In addition, the family would have to give up its ownership of the company and contribute another $1.5 billion by selling another of its pharmaceutical companies, Mundipharma.

Several attorneys general said the agreement was a better way to ensure compensation from Purdue and the Sacklers than taking their chances if Purdue files for bankruptcy on its own.

 Opioid addiction has contributed to the deaths of some 400,000 Americans over the past two decades, hitting many rural communities particularly hard.

The lawsuits against Stamford, Connecticut-based Purdue paint it as a particular villain in the crisis. They say the company's aggressive marketing of OxyContin downplayed addiction risks and led to more widespread opioid prescribing, even though only a sliver of the opioid painkillers sold in the U.S. were its products.