Newly surfaced emails reveal problems going back to 2007 with the ATF office in Phoenix and guns ”walking” across the U.S.-Mexico border.

The emails about the Bush-era problems were given to Congress by the Justice Department as part of the congressional investigation into the ATF’s botched Obama-era firearms trafficking case, dubbed “ Fast and Furious.”

The documents show that the special agent in charge of the ATF’s Phoenix office, William Newell, was involved in a 2007 incident that resulted in guns slipping into Mexico and, later, part of Fast and Furious. Newell was the special agent in charge of the Phoenix office until earlier this year.

The incident arose on Sept. 27, 2007, when ATF agents were conducting surveillance on subjects under investigation for gun trafficking and they hoped to work with the Mexican government to interdict them. The emails’ existence was first reported by The Associated Press Friday night.

Confusion over the incident came to the attention of ATF headquarters from Carson Carroll, who was then the deputy assistant director for the Office of Field Operations.

“ATF agents observed this vehicle [carrying guns] commit to the border and reach the Mexican side until it could no longer be seen,” Carroll wrote in a Sept. 28, 2007 email.  “We, the ATF … did not get a response from the Mexican side until 20 minutes later, who then informed us that they did not see the vehicle cross. For the first time we are working hand in hand with the GOM [Government of Mexico] and providing them with what they want and this is what we get!”

The following day, ATF Acting Director for Field Operation William Hoover was demanding information on the strategy.

“Have we discussed the strategy with the U.S. Attorney’s Office re letting the guns walk? Do we have this approval in writing? Have we discussed and thought thru the consequences of same?” Hoover wrote to Newell and Carroll.  “Are we tracking south of the border? Same re U.S. Attorney’s Office. Did we find out why they missed the hand-off of the vehicle? What are the expected outcomes?

“I do not want any firearms to go south until further notice,” Hoover wrote on Oct 5. “I expect a full briefing paper on my desk Tuesday morning from SAC Newell with every question answered.”

On Oct. 6, 2007, Newell wrote in an email, “I’m so frustrated with this whole mess I’m shutting the case down and any further attempts to do something similar. We’re done trying to pursue new and innovative initiatives – it’s not worth the hassle.”

Newell testified earlier this year about his role in Fast and Furious and acknowledged mistakes.

ATF officials did not respond Friday night to a request for comment about the new documents.

However, a spokesman for Rep. Darrell Issa, R-Calif., a prominent Republican involved in the Fast and Furious probe, said this earlier case appeared different than the Obama-era program.

“In contrast to Operation Fast and Furious, where Mexican authorities were deliberately kept in the dark, this operation was conducted in coordination with Mexican authorities and when supervisors discovered problems that resulted in the loss of a dozen weapons they moved to shut down the effort,” Issa communications director Frederick Hill said. “The committee continues to press the Justice Department for information about this and other operations.”

ABC News’ John Parkinson contributed to this report.