Papa John's founder and chief executive, John Schnatter, called a lawsuit filed last week by rival Pizza Hut "frivolous and simply a public relations stunt."

The suit alleges Papa John's uses deceptive advertising in its use of fresh tomatoes, and on pizza boxes and store signs.

Schattner's comment on the suit is the latest in the year-long battle between Pizza Hut, the world's largest ready-to-eat pizza chain, and the smaller Papa John's, whose advertising has been nothing short of a pie in the face for Pizza Hut.

Animosity seems to have stemmed from a television commercial run last year in which Pizza Hut founder Frank Carney -- who is now a Papa John's franchisee -- steps out in a mock Pizza Hut franchisers meeting wearing a Papa John's T-shirt, where he is proudly introduced as a founder.

"Sorry guys, I found a better pizza," he said, according to the ad.

Then came a round of commercials in which the 3-year-old Papa John's ran favourable results from taste tests comparing the two chains' traditional style pizza.

Pizza Hut, a unit of Tricon Global Restaurants Inc which was spun off from PepsiCo Inc, filed suit in US district court in Dallas this month, challenging its smaller rival's advertising claim of "better ingredients, better pizza."

Pizza Hut is seeking damages and injunctive relief.

"Papa John's is hurting Pizza Hut in the marketplace so they've turned to the courts as a last resort," Schnatter said in response to Pizza Hut's allegations.

Pizza Hut claimed that Papa John's "deceived" customers into believing it uses fresh tomato sauce "when in fact they use cooked and concentrated tomato sauce, stored in cans for 18 months." It also alleges that Papa John's deceptive marketing is included in advertising, point of purchase material, pizza boxes, store signs and other items.

The lawsuit is the third attempt by Pizza Hut in the last nine months to have Papa John's advertising declared deceptive and misleading, Papa John's said in its statement.

"We have always told consumers that our pizza sauce is made with fresh-packed tomatoes that go from the vine to the can in an average of six hours," Papa John's said.

The two pizza chains have gone back and forth alleging various pizza travesties. Pizza Hut issued a statement last week saying Papa John's uses canned mushrooms, and dough that is not made fresh.

Papa John's operates its roughly 1,400 company-owned and franchised units in 43 states and in Mexico City.