The National Organization for Marriage (NOM) last week subpoenaed Fred Karger, founder of Rights Equal Rights, in connection with a federal lawsuit against the Internal Revenue Service (IRS).

Last year, NOM, the nation's most vociferous opponent of gay marriage, accused the Obama administration of leaking its confidential tax return after the Human Rights Campaign (HRC) posted a redacted version of the group's Form 990.

“[T]his was given to our political opponents.  The head of the Human Rights Campaign was a co-chair for President Obama's re-election campaign,” NOM President Brian Brown said during a Fox News appearance. “We need Congress to move forward, we need a thorough investigation, and we need to know for certain if this goes, to see how high this goes. It is not at all encouraging that, again, this was given to a co-chair of President Obama's re-election campaign. That's just wrong.”

Karger has been a leading opponent of NOM, filing state ethics complaints in Maine, California and Iowa.

In an emailed statement, Karger claimed that a 2009 subpoena from NOM was an effort to quiet him.

“NOM subpoenaed me to harass me, force me to spend money and try and scare me away. That didn't work,” said Karger. “We fought back successfully against NOM then, thanks to a great legal team and lots of support. When we see evidence that NOM is not complying with state or federal election laws, we report it to the proper authorities.”

Karger said he would reach out to national LGBT groups for help.

(The subpoena can be viewed here.)