Updated

The apology wasn't enough?

Despite Republican Rep. Darrell Issa apparently telling his Democratic counterpart on the House oversight committee he's sorry for cutting him off during a tense hearing earlier this week, Democrats are mulling the possibility of an ethics complaint.

"His apology didn't go far enough given the level of his antics and offense," one senior House Democratic aide told Fox News. "So there is some talk of filing a complaint."

Democrats tried, unsuccessfully, on Thursday to formally chastise Issa for his actions during Wednesday's hearing. During a heated hearing on the IRS targeting scandal, Issa cut off Democratic Rep. Elijah Cummings' microphone as he tried to make a statement after the hearing had adjourned.

House Republicans blocked a Democrat-backed resolution to condemn Issa's actions.

However, House Speaker Nancy Pelosi told Fox News Friday she knew of no plans to file a formal ethics complaint against Issa. She said she thinks Issa should apologize to Cummings in the "same arena" in which he cut him off.

"You don't call somebody on the phone and say, 'I'm sorry I did that in public,'" she said.

It is unclear whether an ethics complaint will now be filed. But it could work in several ways -- anybody could make a referral to the quasi-governmental Office of Congressional Ethics. Or the House Ethics Committee could decide to take up the issue on its own. Or, any lawmaker could make a referral to that committee.

Issa has apologized to Cummings, but has nevertheless defended his actions.

Issa, R-Calif., speaking on Fox News, acknowledged he could have sat back down and continued to let Cummings speak, but asserted that he did nothing wrong by adjourning the hearing instead.

"You know if I had to do it over again I probably would have sat there for a very long time, let him say a lot of things and then finished, walked away," Issa said. "But you know what, we're all human it was a long day and I didn't break any rules, I did everything according to the rules, he wasn't denied any due process."

Issa also criticized Cummings for breaking the "decorum" of the House to launch what he thinks was a pre-planned event.

"The fact is I did things according to the rules, I followed a script and then Mr. Cummings decided to have quite a hissy fit," he said.

But even some Republicans were disappointed with Issa's response. A senior House Republican aide told Fox News that Issa's conduct was beyond the pale "and now our members have to answer for that."

Fox News' Chad Pergram contributed to this report.