*Editor's note: This story has been updated throughout.

A former Texas environmental investigator tried to blow the whistle on his employer. But instead of helping him, a high-profile Texas law firm tattled on him, he said, triggering a battle that could roil the state’s legal community.

Kent Langerlan, a former Texas Commission on Environmental Quality investigator, is suing Houston-based Baker Botts. After he asked the firm to represent him in a possible whistleblower claim against the TCEQ, he says, Baker Botts let the agency know about the request. The agency later fired him.

In an emailed statement, a spokesman for Baker Botts said the firm "took the appropriate and ethical action under the circumstances."

The details of the lawsuit, filed this month in Harris County district court, stunned several legal experts.

“It's one thing to not represent someone. It's another thing to take the information and turn it over to that prospective client's adversary,” said Kathleen Clark, an expert in whistleblower law at Washington University in St. Louis. “It's a little shocking."

In an email last April, Langerlan asked an attorney at the firm to represent his girlfriend — Audra Benoit, a former enforcement coordinator at the TCEQ — in a whistleblower claim against the agency.

The agency fired Benoit in 2013, listing the reason as “poor performance.” But Langerlan disputed the cause. In the email, which Langerlan’s attorney shared with The Texas Tribune, the former investigator called Benoit a “heralded employee,” who was disciplined for “adamantly following TCEQ procedures and state and federal regulations.”

“Mr. Benoit and I have a huge amount of documentation that validates her argument,” the email said. “And some relevant information they purposely removed remotely.”

The email added that such information would discredit the enforcement division and could "lead you to directly affect clients that Baker Botts represent who have received TCEQ enforcement action.”

The Baker Botts attorney declined to take on the case, and the environmental commission was contacted. The agency fired Langerlan in May, saying his contact with a “Houston law firm" violated ethical standards and professional conduct.

The email included a boilerplate notice that says the information “is intended only for the recipient[s] listed above and may be privileged and confidential.”

"When you contact an attorney with information, even if the attorney initially rejects the case, that initial contact is privileged,” said Josh Davis, the fired staffer’s attorney. “I mean, that's ethics 101."

Baker Botts described Langerlan’s email as untoward.

The email “proposed to provide confidential TCEQ information to us — for use on behalf of clients having matters before the commission if we would represent his girlfriend in an employment case against the commission," Stephen Hastings, the spokesman, said in the emailed statement.

A TCEQ spokesman declined to comment for this article.

Founded in the early days of the Republic of Texas, Baker Botts is among the state’s most prominent law firms. It works for many of Texas' energy giants that have business before the environmental commission. That includes companies seeking permits to build new facilities, or defending themselves against citations for violating environmental law.

The firm has also represented energy companies and industry groups in high-profile battles against federal Environmental Protection Agency rules – often fighting alongside the state of Texas.

Tom Phillips, a former Texas Supreme Court justice and now a Baker Botts lawyer, is representing the Texas Oil and Gas Association in its lawsuit against Denton over its recent ban on hydraulic fracturing. (The Texas General Land Office has filed a separate suit against the city.)

Baker Botts lawyers are generous contributors to Republican political campaigns in the state, giving nearly $100,000 to former Attorney General and now Gov. Greg Abbott in the past 10 years.

Langerlan’s complaint accuses the firm of “gross negligence” in relaying “confidential and privileged” information to the environmental commission.

Texas law protects information a client or would-be client shares with a lawyer. Exceptions include information that “aids anyone to commit or plan to commit a crime or fraud.”

Baker Botts is claiming that exception, according to the complaint.

Clark said the case raises questions beyond simply how far attorney-client privilege extends. Could a state agency, for instance, fire someone for seeking legal advice?

“That’s the allegation,” she said, “and I've got to say that when you think about what whistleblowers do, the safest thing for a whistleblower to do is to reach out to a lawyer and ask for advice.