Washington(CNN) The chief of staff for Veterans Affairs Secretary David Shulkin altered an email and made false statements to a department ethics official that led to taxpayers covering expenses for Shulkin's wife on an official trip to Europe last summer, the agency's inspector general found.

Vivieca Wright Simpson, Shulkin's chief of staff, altered language in an email regarding the logistics of the trip that made it seem as though Shulkin and his wife had been invited to a "special recognition dinner" held by the Danish government. That led to the department paying for Shulkin's wife's more than $4,000 in airfare, according to the report which was released Wednesday.

The Department of Veterans Affairs Office of Inspector General referred those allegations to the Justice Department, which decided not to prosecute at this time, according to the IG report. A VA spokesman did not respond to CNN's inquiry as to whether Wright Simpson remains on staff.

The investigation also found that Shulkin inappropriately accepted tickets to a Wimbeldon tennis match, and used a VA staffer to arrange personal activities for himself and his wife during the trip, saying that the aide "effectively acted as a personal travel concierge" for the couple.

Shulkin, who has been the head of the VA for a little more than a year but was a holdover from the Obama administration, defended himself Wednesday in a blistering statement, calling the investigation and the report a "direct assault on my spouse, my character, and my unblemished record of service to the Veterans Affairs Administration."

Later Wednesday in interviews with the Military Times and USA Today, Shulkin said he intends to comply with all the IG recommendations, even though he disagreed with them. He told USA Today he has already written a check to reimburse the Treasury for his wife's travel.

He told Military Times that he relied on his staff to make "certain decisions" and that he had not intentionally violated ethical guidelines.

"In retrospect, I wish I had asked additional questions of my staff," he said. "There was no intention of misusing government money. I relied upon my staff to make certain decisions."

Shulkin is the latest Trump administration official to be mired in controversy over travel practices. Tom Price, the former Health and Human Services secretary, resigned last year under scrutiny for his use of chartered planes for business purposes. EPA Administrator Scott Pruitt, Interior Secretary Ryan Zinke and Treasury Secretary Steven Mnuchin have also all drawn scrutiny by agency inspectors general for their travel expenses.

'Personal travel concierge'

The report also called into question Shulkin's use of a VA aide, James Gough, to arrange visits to tourist attractions for Shulkin and his wife.

The report includes emails from his wife, Merle Bari, in which she directs Gough to arrange visits to tourist attractions.

In one June 2017 email, Bari wrote to Gough: "Is there earlier flight from Copenhagen? Wimbledon tickets? High tea? Roman baths in [B]ath. Would want to do baths not just tour."

More broadly, VA inspector general Michael Missal said in the report, there were just three and a half days of meetings scheduled over the nine days Shulkin spent in Europe.

"This was time that should have been spent conducting official VA business and not for providing personal travel concierge services to Secretary Shulkin and his wife," he wrote.

Missal also recommended that Shulkin reimburse Victoria Gosling, the former CEO of the 2016 Invictus Games, for the Wimbledon tickets she provided to Shulkin and Bari. Accepting the tickets was a violation of ethics standards, the report said.

According to the report, Shulkin told investigators that he received the Wimbledon tickets as a gift from Gosling, who he described as a friend of his wife's. But, according to the report, when Gosling was interviewed, she could not remember Shulkin's wife's name.

"The OIG concludes that Ms. Gosling gave a gift of the Wimbledon tickets because of Secretary Shulkin's official position," the report states.

When President Donald Trump tapped Shulkin to head the VA in January 2017, he described Shulkin as "fantastic" and said he would do a "truly great job."

On Wednesday, the top senators and representatives on the House and Senate veterans affairs panels, said they were disappointed at the allegations detailed in the report.

"We believe that public officials must be held to a higher standard, and whether intentional or not, misusing taxpayer dollars is unacceptable," Sens. Johnny Isakson of Georgia and Jon Tester of Montana, along with Reps. Phil Roe of Tennessee and Tim Walz of Minnesota, said in a joint statement. "We're counting on Dr. Shulkin to actively address all of the allegations outlined in this report.

Shulkin is scheduled to testify before the House veterans panel Thursday on the VA budget request.