The general counsel of Amazon.com Inc. and four other executives of the online retail giant made individual contributions in May to the reelection campaign of the congressman who is leading a subcommittee antitrust investigation into large technology companies.

First reported by CNBC, general counsel David Zapolsky made a donation of $2,800 May 21 to Rep. David Cicilline, D–Rhode Island, chairman of the House Judiciary Subcommittee on Antitrust, Commercial and Administrative Law.

A spokesperson for Cicilline said in an email to Corporate Counsel that when the hearing was scheduled in July, Cicilline made a policy to not accept political donations from those who may be subject to the hearing.

The hearing, and who would be testifying during it, was announced July 9, and the hearing itself took place July 16. Zapolsky did not testify during the hearing; Amazon’s associate general counsel Nathan Sutton testified on behalf of the company.

The other executives who contributed to Cicilline’s reelection campaign are Amazon’s CEO of worldwide consumer Jeff Wilke, chief financial officer Brian Olsavsky, senior vice president of worldwide operations Dave Clark, and senior vice president of North American consumer Doug Herrington. Herrington, Wilke and Clark all contributed $2,800. Olsavsky contributed $1,500.

A spokeswoman for Amazon said the executive donations were in connection with a fundraising trip to Seattle in which Cicilline visited Amazon’s campus. The trip was planned before the investigation and the hearings were announced.

“No legal ethics rule forbids the GC of a company from contributing to a political campaign, even one made on the eve of his congressional testimony,” Stephen Gillers, professor at New York University School of Law, said in an email to Corporate Counsel. “The only limitation, if one exists, would come not from ethics rules for lawyers but from a company’s policies, if any.”

Google, Facebook and Apple also participated in the hearing in front of the Subcommittee on Antitrust, Commercial and Administrative Law in July. CNBC reported that executives from Apple, Facebook and Google did not make any contributions to Cicilline’s reelection efforts this year.

Cicilline said in a July statement he was not satisfied with many of the answers he and the subcommittee received during the hearing. A week later he wrote a letter to Zapolsky seeking clarifications to Sutton’s live testimony.

“Although I appreciate Amazon’s participating in the hearing, I was troubled by Mr. Sutton’s responses to questions by Members of the Subcommittee,” Cicilline wrote in the letter to Zapolsky. “In several instances Mr. Sutton responded to questions from Members of the Subcommittee by offering either ancillary information or partial and selective responses.”

Cicilline wrote similar letters to Kent Walker, chief legal officer of Alphabet Inc., Google’s parent company, and Jennifer Newstead, general counsel of Facebook. Cicilline attached a series of additional questions to each of the letters hoping to clarify some of the responses given during the hearing.