The U.S. Export-Import Bank has suspended or removed four officials in recent months amid investigations into allegations of gifts and kickbacks, as well as attempts to steer federal contracts to favored companies, several people familiar with the matter said.

One employee, Johnny Gutierrez, an official in the short-term trade finance division, allegedly accepted cash payments in exchange for trying to help a Florida company obtain U.S. government financing to export construction equipment to Latin America, according to a person familiar with the inquiry. Mr. Gutierrez was escorted from the Ex-Im Bank building in April, said two people familiar with the matter.

Mr. Gutierrez's lawyer, Douglas McNabb, confirmed his client had been placed on leave after an investigation by the agency's inspector general, but he wouldn't comment on details of the investigation. Mr. Gutierrez couldn't be reached for comment.

Of the four employees, Mr. Gutierrez's responsibilities were most central to the agency's core mission of financing exports. Two of the others are being investigated over allegations of improperly awarding contracts to help run the agency; the third is being investigated over allegations of accepting gifts on behalf of a company seeking financing, according to people familiar with the matter. The identities of the three couldn't be fully corroborated.

The Ex-Im Bank hasn't disclosed information about the investigations, and declined to comment on Mr. Gutierrez's status, citing privacy laws. Matt Bevens, a spokesman for the agency, said that "the Export-Import Bank takes extremely seriously its commitment to taxpayers and its mission to support U.S. jobs."