Reid blamed Heller Tuesday for failing to get enough votes to pass the measure, a priority of Nevada's casino interests, Roll Call reported.
"It's really a failure in leadership of my friend," Reid said of Heller's efforts during an interview with reporters. "I have done everything within my power to get the Republicans to come up with some votes. This is an important piece of legislation," he said. "It deals with the criminal element."
The Justice Department about a year ago issued a memorandum stating only sports betting would be barred by a law restricting gambling over interstate wires. Casino owners, concerned about the threat posed to their business by unregulated online gaming, have encouraged legislation that would require regulation of the industry.
Reid gave Heller a deadline of early this week to round up the GOP votes needed to pass the legislation, Roll Call said.
Heller said in a letter sent to Reid Monday the House should move first, writing, "I am concerned with attempts to impose a deadline ... providing little, if any, time to reconfirm the necessary support among my conference."
Senate Minority Whip Jon Kyl, R-Ariz., agreed with Heller's assessment, saying those involved in the gaming issue want the bill to originate in the House.
A Democratic aide told Roll Call Reid's office never expected the House to act first. Instead, Reid would exercise his authority as Senate majority leader to find a bill to which he could attach the language.