It’s newest potential headache: bribery. In the bank’s most recent quarterly filing, JPMorgan said it had received questions from the Securities and Exchange Commission about its hiring practices in Hong Kong, which may have included giving jobs to the children of high ranking Chinese officials in return for investment banking assignments for JPMorgan.

JPMorgan says it may have to pay as much as $6.8 billion in fines and fees above what it has already put aside to cover its legal expenses. That’s up from $5.3 billion a year ago. And it’s more than any other U.S. bank. Goldman Sachs (GS), for instance, puts its potential additional legal fines and fees at $3.5 billion. Bank of America (BAC), which was long seen as the bank with the most legal issues, estimates that figure to be $2.8 billion.

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The most costly issue to resolve for JPMorgan: mortgage bonds. Last week, JPMorgan (JPM) disclosed that a government investigation into its mortgage operations in the run-up to the housing bust had concluded that the bank broke laws. No charges have been filed. The Justice Department, the SEC, and the watchdog agency of the Troubled Asset Relief Program are all reportedly looking into what JPMorgan told other banks and officials at the Federal Housing Administration, which insures loans, about the mortgage bonds it was selling in the run-up to the financial crisis.

Until recently, much of JPMorgan’s financial crisis legal woes have related to Bear Stearns and Washington Mutual, which it also acquired in 2008. In October, New York attorney general Eric Schneiderman brought a suit against the bank claiming, among other things, that bankers at Bear Stearns regularly kept payments that were supposed to be passed along to investors to compensate them for defaulted loans.

Josh Rosner, an independent bank analyst who raised alarms about the banks’ mortgage problems back in 2007, did a report on JPMorgan’s legal issues earlier this year. In it, he estimated that investors have lost $190 billion on mortgage loans originated by Washington Mutual. JPMorgan has tried to argue that the Federal Deposit Insurance Corp. should cover those losses since it brokered the deal to sell the troubled WaMu to JPMorgan.

The Justice Department’s latest allegations, though, appear to be related to mortgage bonds that JPMorgan itself underwrote, according to someone with knowledge of the investigations. It’s hard to know exactly which deal got the bank in trouble. JPMorgan said the government is looking at mortgage deals that were backed by subprime and Alt-A home loans that the bank sold between 2005 and 2007.

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The government has been looking into the mortgage operations of a number of big banks. It appears regulators are concerned banks sold bonds with mortgage loans that were riskier than what they were telling investors. And nearly every big bank has been sued by investors who lost money on the deals. A JPMorgan spokesperson declined to comment on the latest allegations.

Jason Goldberg, an analyst at Barclays, says that JPMorgan from 2005 to 2008 sold $285 billion in so-called private mortgage bond deals, meaning they were not insured by Fannie Mae or Freddie Mac, though some of those deals were bought by Fannie or Freddie. Many of those deals contained loans that were made to subprime or Alt-A borrowers. (An Alt-A loan was one that either had a very low or no downpayment, or where the lender had not verified a borrower’s income.) Goldberg estimates that investors have lost lost $48 billion on those deals. An additional $91 billion is still outstanding on the loans contained in JPMorgan’s deals, of which $22 billion is to borrowers who are two months or more behind on their mortgage.

Iowa-based insurer CUNA Mutual says it invested $65 million in mortgage deals sold by JPMorgan in 2005 and 2006. The deals weren’t great from the start. One of the bonds bought by CMGF’s Iowa-based division CUNA Mutual had a BBB rating. But the firm says it felt comfortable with the deals because it was buying them from JPMorgan. What’s more, it says its manager had been buying mortgage bonds for over 15 years at the time and was a regular at industry conferences where he would bump into JPMorgan bankers, who would pitch him deals.

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In November 2005, CUNA put just over $12 million in a mortgage bond deal called CWALT 2005 – 57CB, which got a AA rating from Fitch. The name refers to the fact that the loans in the deal came from now-defunct mortgage lender Countrywide. According to JPMorgan’s prospectus, the loans in the deal had an average loan-to-value of 73%, meaning on average, borrowers had made down payments equal to about 27% of the homes they were buying or refinancing. Just 4% of the loans were made to borrowers who put down less than 10%.

In fact, CUNA later found out that the average LTV was 108%, meaning the borrowers had, on average, been lent 8% more than the houses they were borrowing against were worth. What’s more, 57% of the loans in the deal CUNA bought were made to borrowers who had put down less than 10%, quite a bit more than the 4% JPMorgan said.

The deal has since been downgraded to a D by Fitch. On Thursday, CUNA’s owner Wisconsin-based CMFG sued JPMorgan. It says it was misled.