Last season, both Oregon and Washington went to great lengths to hide their sideline signals while playing Arizona State at Sun Devil Stadium.

Both head coaches accused ASU head coach Todd Graham and his staff of "diligently working to steal signs."

Now it's Washington State's turn to take the field Saturday night in Tempe, and Cougars coach Mike Leach voiced the same concerns in a tirade of allegations this week.

"They have a whole command center that's designed around this stuff," he said. "You've got to keep an eye on them because they'll steal signs and they're pretty clever about it. It's like breaking the enigma code with them."

Graham responded to the claims Tuesday, denying any spying.

"I'll make this perfectly clear: We do everything exactly by the rules, period," he said. "I'm not going to be involved in things like that, that are ridiculous ... We take a great deal of pride in the integrity that our program has."

Last year, the Pac-12 investigated the situation and found no wrongdoing.

Leach isn't buying it, though.

"I think we ought to do a full-on investigation about how they're doing it and whether it's in the rules," he said. "That is a very unsavory practice that they have so we'll have to do what we can to defend ourselves against it."