Long before Apple (AAPL) and Samsung returned March 31 to U.S. District Court in San Jose, California, for another titanic legal battle, Google (GOOG) agreed to handle a segment of the Korean manufacturer’s defense against the iPhone maker’s patent infringement allegations and to underwrite a portion of its legal costs.

According to accounts, Google attorney James Maccoun confirmed emails in which the Android platform parent said it would partially or completely financially back Samsung against infringement charges on four Apple patents. Apple dropped claims against two of the patents in pre-trial negotiations. The remainder involve background synchronization and universal search that concerns Google-developed apps such as the search box and Gmail. Device makers licensing the proprietary apps Gmail and Google Search box cannot alter the code, unlike the open source aspects of Android.

In the emails, which date from April 2012, Google agreed to "defend and indemnify" Samsung over using technology Apple said violated its patents, reports said.

"I see [indemnify] as a general term relating to providing a defense against claims and then can mean other things depending on the outcome of litigation," Maccoun said during his deposition, according to accounts. "I understand that Google is defending Samsung and that this is reflected by emails."

Google is helping defend Samsung based on a “Mobile Application Distribution Agreement” between the companies, under which the Korean vendor agreed to include Google applications such as Gmail and Search on its Android-based smartphones and tablets.

Neither Google nor Samsung are saying how much backing so far has shuttled Samsung’s way or how defense costs were determined and money allocated, reports said. The companies’ arrangement details aside, it’s clear Google, which at the beginning of the trial was regarded as a minor participant, is instead an active collaborator in Samsung’s defense.

Apple reportedly introduced evidence of Google’s financial and legal support of Samsung to question the Korean company’s veracity. Samsung asserted in September 2012 in responding to an Apple interrogatory that it was “not currently seeking indemnification from any third party.”

Maccoun’s confirmation of the emails in which Google agrees to back Samsung’s defense date from April to December 2012 and appears to directly contradict Samsung’s response.

In the current trial, Apple is pursuing the same thing as in other litigations with Samsung—banning sales of Samsung Galaxy products, a prize that in many ways would be a far bigger win than pocketing the $2 billion in damages the iPhone maker seeks.

For Samsung’s part, scoring a victory against Apple’s key technology would deliver it a long-sought counterpunch, even if the Korean vendor only is asking for $7 million in damages.