Home Depot has been in contact with the U.S. Secret Service about an alleged major breach of customer and credit card data that came to light this week, a law enforcement source told Reuters.
Any investigation by the Secret Service appears to be at a very early stage, the source said.
The Secret Service usually is the lead agency in federal criminal investigations into complex breaches of credit card and other consumer data.
Another law enforcement source said the FBI, which also sometimes participates in such investigations, does not appear to be involved. It is unclear whether the U.S. Department of Justice is playing any role.
Customer data could have been stolen from nearly all of Home Depot's 2,200 stores in the United States, according to new information released on Wednesday by security website KrebsonSecurity.
Home Depot shares were up about 1 percent in early U.S. trading.