Two people from Taiwanese companies were questioned as part of a probe into pagers that exploded while being used by Hezbollah operatives in Lebanon, investigators said Friday, as top officials insisted the devices were not from the island.

Questions and speculation have swirled over where the devices came from and how they were supplied to the militant group after hundreds of pagers and walkie-talkies detonated across Lebanon on Tuesday and Wednesday, killing at least 37 people and wounding nearly 3,000.

The New York Times reported this week that Israel had inserted explosive material into a shipment of pagers from Taiwan’s Gold Apollo, citing American and other anonymous officials.

But Gold Apollo head Hsu Ching-kuang denied producing the devices, pointing the finger instead at Hungary-based partner BAC Consulting KFT, which Gold Apollo had allowed to use its trademark.

cLocal media reported that the second person questioned was Wu Yu-jen, a representative connected to BAC Consulting KFT, who had set up a company based in Taipei called “Apollo Systems”.

“Our country takes the case very seriously,” said the prosecutors’ office in Taipei’s Shilin district in a statement Friday.

“We instructed the Investigation Bureau’s national security station to further interview two people from Taiwanese companies as witnesses yesterday.”

The two witnesses were allowed to leave after multiple rounds of questioning.

“We will clarify the facts as soon as possible such as whether Taiwanese companies are involved or not,” the office said.

It also said investigators had searched four locations, including in New Taipei City’s Xizhi district, where Gold Apollo is located, and in Taipei’s Neihu district.

Neihu district is the listed address of Apollo Systems, according to a company registry website, which showed that the firm was established in April this year.

Wu did not speak to reporters when she was brought in for questioning Thursday, according to local TV footage.

Economic Minister Kuo Jyh-huei told reporters Friday that Gold Apollo’s made-in-Taiwan pagers consisted of components that were “low-end IC (integrated circuits) and batteries”.

“These things would not explode,” he said, adding that Gold Apollo had exported 260,000 pagers in the past two years and “there has never been an explosion.”

When pressed on the pagers in Lebanon used by Hezbollah operatives, he said: “We can be certain that they are not produced in Taiwan.”

Premier Cho Jung-tai also reiterated Friday that “the company and Taiwan did not directly export pagers to Lebanon.”

Earlier this week, Gold Apollo said the pager model mentioned in media reports “is produced and sold by BAC.”

But a Hungarian government spokesman said BAC Consulting KFT was “a trading intermediary, with no manufacturing or operational site in Hungary.”