There’s good reason Washington, D.C. is frequently referred to as a “swamp.”

In the weeks leading up to the House antitrust investigation into major tech companies, five Amazon executives made healthy donations to the chair of the subcommittee heading up the effort.

The donations, totally $12,700, were made to Rep. David Cicilline (D-RI) chairman of the House Antitrust Subcommittee, according to CNBC.

The contributions came two months before Cicilline’s panel questioned executives at Amazon, Apple, Facebook, and Google at a hearing that was part of a broader antitrust investigation.

The Amazon executives were identified as Jeff Wilke, CEO of worldwide consumer, CFO Brian Olsavsky, general counsel David Zapolsky, SVP of worldwide operations Dave Clark, and SVP of North America consumer Doug Herrington.

Each executive donated the $2,800 maximum, except for Olsavsky, who gave $1,500, with the donations coming in a three-week period beginning in late May — this being before the antitrust probe announcement, and before the July hearing was scheduled, CNBC reported.

Which would suggest someone may have tipped Amazon about what was coming down the track. Or, as some experts suggested to CNBC, it was just fortuitous timing by the company in reacting to its heightened urgency over growing regulatory scrutiny.

According to the filings cited, no executive from Apple, Facebook or Google donated to Cicilline’s campaign this year.

A spokesperson for Cicilline told CNBC the chairman put in place “a formal policy of refusing campaign contributions from companies and executives that may be subject to scrutiny.”

This coming on the day the subcommittee launched its antitrust investigation, and after the Amazon executives cut their checks.

There were reportedly other possible reasons the Amazon executives may have wanted to show support for Cicilline.

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Cicilline introduced the Equality Act, which prohibits employee discrimination on the basis of sexual orientation or medical condition, and was a key supporter of raising the federal minimum wage — two initiatives the company supports. Those are the only two issues that all of Amazon’s registered lobbyists have lobbied for in the past, according to a person familiar with the matter. At the same time, filings show that only one Amazon executive has donated to Cicilline in the past: Vice President of Public PolicyBrian Huseman contributed $250 in 2012.

Given Cicilline’s comments after the July hearing, it doesn’t appear that the money had much effect, as he was critical of Amazon’s testimony, citing “lack of preparation” and “purposeful evasion.”

“I was deeply troubled by the evasive, incomplete, or misleading answers received to basic questions directed to these companies by members of the subcommittee,” the chairman said in a public statement, according to Bloomberg News.

Cicilline previously said he was particularly interested in investigating the Amazon purchase of Whole Foods.

“Competition is essential for a healthy economy. That’s true across the board. Amazon’s proposed purchase of Whole Foods could impact neighborhood grocery stores and hardworking consumers across America,” said Cicilline in a public statement. “Congress has a responsibility to fully scrutinize this merger before it goes ahead. Failing to do so is a disservice to our constituents.”

For now, Amazon is remaining mum on the donations, declining to offer CNBC any comment on its story.