U.S. Senator Elizabeth Warren asked the Labor Department for an update on its investigation into Wells Fargo & Co.’s sales practices after she was unable to access a website the agency set up to track complaints from the bank’s employees.

“I am concerned that the Department of Labor has removed the website where Wells Fargo’s employees who were victims of the company’s fraudulent actions could file labor complaints or report illegal activity,” Ms. Warren wrote in a letter Thursday to Edward Hugler, acting Labor secretary.

Ms. Warren, a Massachusetts Democrat, said she received a “page not found” error this week when she tried to access the website and asked for more information about the status of the agency’s review of the company’s sales practices. Ms. Warren said the page was working on Jan. 20, the day President Donald Trump took office.

Yet Steve Barr, a spokesman for the Labor Department, said the website was taken down on Jan. 9, before Mr. Trump’s inauguration. He said he didn’t know the reason and that the agency hasn’t been informed by the White House about how the administration wants to proceed on investigating Wells Fargo.

“We have been given no direction from the current administration on matters involving Wells Fargo,” Mr. Barr said.

Lacey Rose, a spokeswoman for Ms. Warren, said she had no immediate comment on the day Mr. Barr said the page was removed.

PHONY ACCOUNTS

In September, the Labor Department said it started an investigation into Wells Fargo after the San Francisco-based lender was caught creating legions of phony accounts for customers without their knowledge. Ms. Warren and a group of Democratic lawmakers had asked the agency to look into whether the company violated wage and overtime rules while pushing branch workers to meet aggressive sales quotas.

Under the Trump administration, there have been changes on other federal agency web pages. Information about climate change has been removed from various government sites. The White House website no longer has a section on the topic. An EPA page that answered “common questions” about global warming is gone. And reports on greenhouse gas emissions have vanished from the State Department’s internet site.

Mr. Hugler was named acting secretary after the exit of Tom Perez, the last chief of the agency under President Barack Obama. Mr. Trump’s pick to lead the agency, Andrew Puzder, chief executive officer of CKE Restaurants Inc., has not yet been confirmed by the Senate.

The bank has apologized for breaking customers’ trust, pledged to make them whole and said it’s ending sales incentives that have been blamed for the abuses.