Meanwhile, Netanyahu's wife, Sara, was being questioned about the case in a different location.
A police spokesman declined comment on the report that the prime minister was questioned. Elovitch is suspected of being part of a bribery deal, in which Bezeq received regulatory and financial benefits from the Communication Ministry, which Netanyahu headed between 2014 and 2017 in addition to his capacity as prime minister.
A final case, dubbed 3000, is being investigated separately and has involved Netanyahu allies, but the prime minister has not been named as a suspect.
The firm has denied wrongdoing.
"Tendentious and lying leaks against Mrs. Netanyahu are meant to hurt the prime minister and the Likud government".
The case involves accusations that Bezeq owner Shaul Elovitch had instructed the Walla news website, which he owns, to provide Netanyahu with positive coverage.
This, said the TV channel, turns Sara Netanyahu into a suspect in the case.
Last month, Israeli police recommended that the prime minister be indicted for a series of serious corruption charges including bribery, fraud, and breach of trust in two other cases, "case 1000" and "case 2000".
The case centers around Netanyahu's previous term as prime minister when he also served as Minister of Communications.
"We want to see Netanyahu go to trial and, if needed, go to jail or go home. Let our people go free from all the corruption surrounding the government and the head of it", said Shimrit Orr, 72, a writer, from Tel Aviv.
He's stated that he will seek a fifth term in a nationwide election due in late 2019.
Mr. Netanyahu is accused of accepting almost $300,000 in lavish gifts from Hollywood mogul Arnon Milchan and Australian billionaire James Packer.
Case 2000, said police, involved deals made between Netanyahu and Arnon Mozes, publisher of the popular Israeli daily Yedioth Ahronoth.
Thus far, Partners in Netanyahu's governing coalition have stood by him, stating they were awaiting the attorney-general's next moves. During that time, Walla's coverage notably changed to favor the Netanyahu family, and Bezeq was given permission, among other things, to buy the satellite cable provider Yes, overriding antitrust issues, and to renege on its commitment to lease out its infrastructure to telecom competitors so they could provide competing fixed line and internet services. But surveys also show strong support among Netanyahu's core base, while the Likud Party remains ahead of all other Israeli parties.