This story was updated at 9:18 pm with a comment from the RGA

The law firm that wrote the Chris Christie-sponsored report clearing the governor of any wrongdoing in the New Jersey bridge scandal made a sizable donation to the Republican Governors Association, which Christie heads, days before the report's release.

The law firm of Gibson Dunn & Crutcher donated $10,000 to the RGA nine days before it released a report - paid for by New Jersey taxpayers - blaming September's lane closures to the George Washington Bridge solely on aides and allies and pinned no responsibility on the governor, as reported today in The Record of North Jersey.

Gibson Dunn & Crutcher lawyers were paid $650 per hour for their work examining documents surrounding the lane closure that led to their report released March 24. The law firm made its donation to the RGA March 18, according to tax records.

Christie spoke exclusively with ABC News' Diane Sawyer the same day the report was released, telling her he was "relieved" to have the facts.

He rejected any suggestion that the outside law firm appointed by his office would "whitewash" its findings to protect him.

"These people have their own professional and personal reputations," he said. "Six of them were former federal prosecutors. They're not going to whitewash anything for me and put their reputations at stake."

(Matt Rourke/AP Photo)

The Los Angeles-based law firm defended its actions.

"Gibson Dunn's annual contributions to the Republican Governors Association long predate our retention by the Office of the Governor and even predate when the current Governor was first elected to office," Gibson, Dunn & Crutcher spokeswoman Pearl Piatt said in a statement to ABC News today.

"The firm has donated to the RGA since 2009 at the behest of Bill Kilberg, a partner in the firm's Washington, DC office who has served on the RGA's Executive Roundtable since 2009."

Christie's office directed ABC News to Gibson, Dunn for comment.

The Record also reported: "The law firm made two donations to the Republican Governors Association in 2012 each for $10,000, one on Feb. 20 and the other on Dec. 31 of that year. The group donated $15,000 in 2011 and $10,000 in 2010 and 2009."

It has not donated to the Democratic Governors Association this year, nor the previous two years.

The Republican Governors Association announced in early April that it had raised $23.5 million in the first quarter of 2014, doubling the amount raised at the same time in 2010.

RGA press secretary Jon Thompson told ABC News: "The RGA raises funds to elect and support Republican governors. We had a large amount of donations from many individuals and entities across the country because they support the pro-jobs, pro-growth agendas 29 Republican governors are delivering for their states."