An electronic device removed from a polling station during the West Tyrone by-election yesterday after allegations of rule breaches was a Kindle e-reader, Sinn Fein has said.
The SDLP had reported the use of a device to the chief electoral office and called for "urgent action".
Under electoral rules, polling agents are not permitted to use any type of electronic device.
Chief electoral officer Virginia McVeigh confirmed that one electronic device was removed from a polling station in Strabane.
She said she had handled the matter personally as the incident had happened when she was at the station.
Ms McVeigh, who had been visiting some of the 41 polling sites located throughout the constituency, said: "It was one device.
"I dealt with it and it (the electronic device) has gone."
However, Sinn Fein slammed the response, saying the election worker had been given permission to use the e-reader and had been openly reading a book for two hours.
Sinn Fein election agent Barry McColgan went on to say: "For the SDLP to subsequently claim that this amounts to electoral fraud is as spurious as it is pathetic."
Mr McColgan added that the SDLP was itself guilty of breaching electoral rules.
"In fact, it has been confirmed that one of the SDLP representatives who raised the complaint was not a named polling agent and was therefore breaching electoral law by being in the building," he said.
"If anyone has questions to answer about this incident, it is the SDLP."
However, SDLP West Tyrone election agent Simon Ashley said: "It is absolutely essential that electoral law is fully enforced and Sinn Fein should remember that no one is above the law."
He added: "Sinn Fein know that the use of any electronic item is prohibited inside a polling station."