If the grandfather and grandson walking together in Sen. Rick Santorum's Internet re-election ad look familiar, it could be because the same two actors are in a TV ad that a group called Americans for Job Security is running in support of him.

A spokeswoman for Santorum, R-Pa., has repeatedly denied any connection between Santorum and the group. But the campaign for Bob Casey Jr. — the leading Democratic challenger in the Senate race — said Friday the coincidence was too much to be ignored.

"I think it raises a lot of questions," said Larry Smar, a spokesman for Casey, the Pennsylvania treasurer who is leading in polls. "Someone isn't shooting straight."

Michael Dubke, president of the Republican-leaning group, and John Brabender, Santorum's media consultant, denied in separate interviews that the two sides had talked or collaborated in any way.

They each said it was a coincidence they used the same stock footage in their respective ads. Both ads tout a plan by Santorum that he says would guarantee Social Security for those 55 and older.