This excerpt from a search warrant affidavit recently unsealed at the request of The Washington Post shows the chairwoman of former mayor Vincent C. Gray’s 2010 campaign raising concerns about the activities of one of his longtime political advisers. The off-the-books campaign effort on Gray’s behalf became the subject of a long-running federal campaign finance investigation.

The week before the 2010 primary election for the District’s highest office, the chairwoman of Vincent C. Gray’s campaign had concerns. She was worried that Gray’s longtime political adviser was running an off-the-books campaign — a shadow campaign that would become the central focus of a long-running federal investigation.

The campaign chairwoman shared her anxiety in an email about the activities of the adviser, Vernon Hawkins.

“Vernon is doing something off the books,” she wrote to Gray’s then-girlfriend in an email obtained by law enforcement and described in a sworn FBI affidavit.

“I’m not in the loop (and don’t want to be)!”

Gray’s then-girlfriend told law enforcement officials that she relayed those concerns to Gray, according to court documents that were unsealed at the request of The Washington Post.

Vincent Gray chats with campaign chairwoman Lorraine Green in April 2010 as Gray makes the official announcement that he is challenging Mayor Adrian Fenty. (Marvin Joseph/The Washington Post)

In a recent interview, the ex-girlfriend, Linda Mercado Greene, said she was “candid and upfront” with federal investigators. She said an account of the email in the newly released documents was accurate, as were the accounts of other exchanges she had in 2010 with Gray’s campaign chairwoman.

Greene no longer has a copy of the 2010 email. “This is buried,” she said. “I have moved on.”

She told The Post that it was her practice to relay messages to Gray but that because of the passage of time she could not say with certainty that she shared the worries.

“I think I did,” Greene said. “I would say it’s most likely I did. I can’t say I definitely did.”

Gray has vigorously denied knowledge of the illegal spending and was not charged in the now-closed case.

“This matter is in the past for Vince. We’ve made that clear,” said Chuck Thies, Gray’s campaign spokesman.

Gray has launched a political comeback, running in the June 14 primary for the Ward 7 seat on the D.C. Council.

Vincent C. Gray and former girlfriend, Linda Mercado Greene in 2011. (Rebecca D'Angelo/for The Washington Post)

Greene, a public relations strategist, is supporting Gray’s rival, Yvette Alexander.

Whether Gray was alerted to “something off-the-books” by his girlfriend and his campaign chairwoman was an important piece of information for federal prosecutors as they prepared a case against the former mayor.

Political donor Jeffrey E. Thompson poured more than $650,000 into the unreported shadow campaign. Thompson and his associate, Jeanne Clark Harris, told investigators that Gray knew about the secret spending and personally asked for the campaign money, according to court documents.

As a result of the investigation, a half-dozen people pleaded guilty to felony charges directly related to the illegal spending that was closely coordinated with Gray’s official, legal campaign.

Prosecutors are set to file sentencing papers this week that are expected to spell out whether they still believe Thompson’s account of his interactions with Gray. If prosecutors say Thompson has fully cooperated, his plea agreement calls for a reduced sentence of no more than six months in prison — far less than the seven years he could have faced.

Thompson is scheduled to be sentenced four days before the D.C. Council primary contest. Harris’s sentencing follows in early July.

U.S. Attorney Channing D. Phillips shut down the nearly four-year probe in December soon after taking over the office from the two men who launched the investigation. In closing out the investigation, Phillips said in a statement that the evidence was “likely insufficient” to sustain a conviction against any other individuals.

During the probe, authorities had gathered thousands of emails.

The names of Gray’s ex-girlfriend and his campaign chairwoman are redacted in court filings, but Greene said she and the chairwoman, Lorraine Green, are the people cited in the affidavit about the worries about “something off the books.”

Lorraine Green’s attorney, Thomas C. Green, said he had no information or recollection of the specific email or whether his client communicated her concerns directly to Gray. The Greens are not related.

“They had all her emails. She explained them fully, and it didn’t create any issues” for her, he said.

Excerpts from that email message show that the get-out-the-vote effort backed by Thompson attracted the campaign chairwoman’s attention the week before Gray won the Democratic primary. His victory over sitting mayor Adrian M. Fenty all but assured Gray’s ascension from council chairman to mayor in a city where more than 75 percent of voters are registered Democrats.

Lorraine Green, then an Amtrak executive, had gotten to know Gray when they both worked for former mayor Sharon Pratt in the 1990s. Gray has described her as his “closest friend.”

The timing of the fretful email was important. Court records show that a key date prosecutors focused on was Sept. 3, 2010, when they say a dinner meeting occurred at Harris’s apartment. Harris and Thompson told investigators that Gray personally asked Thompson at that dinner meeting to fund a get-out-the-vote campaign, court documents show.

The day after, Harris called Hawkins, Gray’s longtime political adviser. Hawkins later admitted in court that he had helped design the plan for the shadow campaign and coordinated activities with the legal campaign. Hawkins was sentenced to six months in prison.

Hawkins “understood from Harris that the dinner meeting with the candidate was to green-light the shadow campaign,” prosecutors said in court filings related to Hawkins’s sentencing.

The email with the worries went to Gray’s then-girlfriend two days later, Sept. 6.

“Maybe he is doing his own GOTV,” the chairwoman of the legal campaign wrote in a reference to Hawkins’s get-out-the-vote activity.

Lorraine Green, the chairwoman, asked Gray’s girlfriend to “find out what that is,” according to the affidavit.

Gray’s now ex-girlfriend told law enforcement officials that Green also asked her to have Gray contact her about “the other campaign” in two conversations.

Green described the other campaign as “something that Hawkins and Harris were doing and which was driving Green crazy,” investigators said in their affidavit.

Gray’s ex-girlfriend “described passing the messages along” to Gray, according to the affidavit.

The U.S. Attorney’s Office declined to provide the full text of the email to The Post, saying it does not typically share evidence that has not been filed in court.

During the campaign, Gray’s ex-girlfriend said people were constantly giving her messages to relay to Gray. She almost never forwarded emails and was more likely to send word by phone or text, she said.

At the time of Green’s email message, Gray’s ex-girlfriend said she would not have understood the meaning or significance of the phrase “something off-the-books.” It was not until early 2012 that The Post reported that investigators were focused on an illegal shadow campaign.

If she did convey the concerns to Gray six years ago, she said this month, she can’t say for sure “whether he heard me, whether he listened.”

“Sometimes, people don’t listen,” she added, joking about relationship dynamics.

In a campaign environment, Gray’s spokesman said candidates are “told all kinds of things all the time. This individual is saying she’s not certain she relayed that message,” Thies said.

After Gray’s election, while they were still a couple, Greene asked Gray “to see if Thompson could assist her in finding a job,” according to the affidavit, and “Gray agreed to ask Thompson to assist her with finding a job.”

She recently confirmed asking for job help but said it was Harris, one of her mentors, who arranged to hire her for a $45,000 six-month public relations contract. Toward the end of the contract, she learned that the money for it was coming from Thompson, Greene said.

Prosecutors previously mentioned Thompson’s payments through Harris to Gray’s “close personal friend” in documents related to Thompson’s plea deal and added that the new mayor “thanked Thompson for getting work for the friend.”

Gray and Greene went public with their relationship in December 2010, after Gray had become mayor-elect. They split up more than two years ago. Greene is not in contact with Gray or his former campaign chairwoman. She declined to go into more detail about her personal life.

Greene remains active in local politics and held a fundraiser this month for Alexander, Gray’s Democratic primary rival.

“In order for East of the River to progress and move forward, it’s important to keep the council members we have,” said Greene, who lives in Anacostia in Ward 8.

When asked why she was not supporting her former beau, she said: “I just don’t think it’s a good choice for him. He has done his public service, and now he should look at other careers.”