Mustapha Fawaz, Abdallah Thahini and Talal Ahmad Roda were arrested in May after the discovery of an arms cache in a residence in the northern Nigerian city of Kano.
They have been accused of plotting attacks against Western and Israeli targets in Nigeria and have denied the charges.
An Israeli embassy spokesman did not immediately respond to requests for comment.
Fawaz testified today that, after his arrest in Abuja, a security official told him "some European friends" wanted to ask him questions.
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Fawaz said one of the interrogators identified himself as a Mossad agent. He said they were "crude and nasty."
"They handcuffed my hands behind my back for days. I lost count because they did not allow me to sleep for several days," Fawaz said, denying membership in Hezbollah.
"They asked if I have any weapon in Abuja ... They asked if I have been asked to do any operation in Nigeria or anywhere else in the world," Fawaz said.
"I was interrogated in Arabic. I asked to be interrogated in English, but they refused. Most of them are weak in English. They are not Europeans, but Israelis."
Fawaz said no Nigerian official was present during the sessions.
"They asked me about my link with Hezbollah, but they concentrated more on Lebanon -- whether I knew if there are weapons stored in the south of Lebanon or the identities of people who have been trained by Hezbollah," said Fawaz.
He claimed to have collapsed after being denied sleep for five days by the foreign interrogators.