PHOENIX — Thousands of Arizona motorists who got photo radar tickets might be able to ignore them if a new lawsuit is successful.

And those who already paid may be able to get their money back.

Legal papers filed in Maricopa County Superior Court contend that the citations issued by Redflex Traffic Systems before the at least the first week in August are illegal. That is because the company, which operates speed enforcement cameras for the Department of Public Safety and several Arizona communities, was operating radar guns which had not been cleared for use in this country.

Attorney Thomas Moring said that, at the very least, it entitles his client, James Tavernetti, to refuse to pay the photo radar ticket that was issued by the Town of Paradise Valley in June. A mobile photo radar unit operated for the town by Redflex clocked him as speeding.

But Moring also is asking Judge Eddward Ballinger to block any other state or local government which has issued such citations from enforcing them. That includes not only Paradise Valley and the Department of Public Safety but also could affect Chandler, Prescott Valley, Tempe and Pinal County.

And Moring said the case could ultimately be expanded to cover those who paid the tickets without protest because they didn’t know Redflex was operating the radar guns without legal authority.

Central to the dispute is the admission last month by Karen Finley, president of the Scottsdale-based company, that the particular type of radar units Redflex imported into the United States had not been approved by the Federal Communications Commission. That approval is required of any device which transmits radio waves.

DPS, on hearing the admission, took their two photo radar vans off the road until FCC-certification came through. But Lt. James Warriner acknowledged that the two vans already had issued about 4,800 citations since first being deployed last November.

In the lawsuit, Moring charges Redflex with negligence, saying the company knew or should have known that it was operating the radar units illegally. He also is alleging consumer fraud, saying the company concealed the illegal operation for its own financial gain, meaning the money it makes under its contract with Paradise Valley for each citation issued and paid.

In disclosing the problem last month to the state, Finley offered to refund any fines paid.

But DPS spokesman Bart Graves said his agency does not consider that necessary. Graves said that it appears the radar units were operating properly — at least in the sense that they were accurately recording the speed of motorists.

Moring, however, said even if that is true, it’s legally irrelevant.

He said Redflex did not have the legal right to turn the radar units on anywhere in this country before they were FCC certified. And if they were not turned on, Moring said, the tickets never would have been issued.

Jay Heiler, a spokesman for Redflex, said he expects the lawsuit to be thrown out.

“The radars in question have always been approved and they’ve always been accurate,’’ he said.

“They are now certified for FCC purposes,’’ Heiler continued. “And, in fact, the accuracy of the radar has never been brought into question.’’

The lawsuit comes as Redflex is embroiled in a related legal fight over the decision by DPS to give it a contract to provide at least 100 fixed and mobile speed cameras. An attorney for American Traffic Solutions, also based in Scottsdale, has filed an appeal, arguing that Redflex could not legally bid because it was operating its existing radar guns illegally, including those in the two DPS vans.