The battle between Mitek Systems and USAA continues. The San Diego, Calif. technology company is adding to its lawsuit against the San Antonio financial services company.

The original Mitek lawsuit claims that USAA is infringing on five patents on Mitek's mobile remote deposit capture technology -- the method by which users scan checks and deposit them with a scanner or smartphone camera.

Mitek is now adding defamation and unfair business practices to the list of accusations.

The litigation stems from a contract dispute between the two companies during a renegotiation. Mitek and USAA started working together 2008, not long after Mitek began marketing its check capture technology.

Since March, the San Diego, Calif. company which primarily provides remote deposit capture, has been in a back and forth with USAA.

First, USAA said that, "Mitek misappropriated USAA's proprietary and confidential information while working under contract for USAA, and then took numerous steps to claim it as its own."

Then, Mitek launched its counter suit.

"They claimed that we misappropriated their trade secrets," says Mitek chief executive Jim DeBello.

When asked which trade secrets, he said: "You have to ask them that. It's a very good question, and they haven't told us anything."

In the end, Mitek is fighting for its reputation.

"[Our] market cap has decreased over $200 million ...because shareholders believe that we are being challenged on the intellectual property that we have created," says DeBello, adding that USAA's claim that it stole some of the bank's trade secrets is hurting Mitek's bottom line.

USAA provided this statement on the matter: "USAA is confident in the merits of our case. We look forward to presenting the facts surrounding this case in a court of law."

"Obviously we are not trying to pick a fight with an industry player," says DeBello. "We have reached out in several occurrences to try and engage them to withdraw their claims or to otherwise come to a resolution. That has met with no response."