PricewaterhouseCoopers said it is working with the U.S. Secret Service after allegations that the tax returns of client Mitt Romney were stolen.

Mitt Romney

“We are aware of the allegations that have been made regarding improper access to our systems,” said a statement forwarded by PwC spokesperson Tanja Sullivan. “We are working closely with the United States Secret Service, and at this time there is no evidence that our systems have been compromised or that there was any unauthorized access to the data in question.”

The tax returns of the Republican presidential candidate were reportedly stolen from a PwC office in Franklin, Tenn. The hacker sent anonymous messages to PwC, as well as Romney’s campaign offices demanding a ransom of $1 million in a difficult-to-trace online currency known as Bitcoins for the tax returns, according to the Associated Press. He also reportedly sent packages to local Democratic and Republican campaign offices with a thumb drive containing some of the documents. In addition, he posted a message on a Web site popular with hackers known as Pastebin threatening to disclose the tax returns. Romney has refused to release any tax returns prior to his 2010 taxes, despite pressure from the Obama campaign.

“Dear PricewaterhouseCoopers LLP,” the hacker wrote. “Using your Office @ 830 Crescent Centre Drive, Suite 260, Franklin, TN 37067  Telephone: [1] (615) 503-2860 we were able to gain access to your network file servers and copy over the tax documents for one Willard M Romney and Ann D Romney. We are sure that once you figure out where the security breach was, some people will probably get fired but that is not our concern.

“All major news media outlets are going to be sent an encrypted copy of the most recent tax years that your company had on file since you did not have them all in a convenient electronic form. The years before 2010 will be of great interest to many. If the parties interested do not want the encrypted key released to the public to unlock these documents on September 28 of this year then payment will be necessary.

“The deal is quite simple. Convert $1,000,000 USD to Bitcoins (Google if you need a lesson on what Bitcoin is) using the various markets available out in the world for buying. Transfer the Bitcoins gathered to the Bitcoin address listed below. It does not matter if small amounts or one large amount is transferred, as long as the final value of the Bitcoins is equal to $1,000,000 USD at the time when it is finished. The keys to unlock the data will be purged and what ever is inside the documents will remain a secret forever.

“Failure to do this before September 28, the entire world will be allowed to view the documents with a publicly released key to unlock everything.”

Local police in Franklin told the AP there was no break-in at the PwC offices or any alarms that went off.