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The Uzbek man charged with using a truck to kill eight people on a Manhattan bike path last year was recorded on an F.B.I. wiretap the day before the attack and was heard on other calls going back three years, according to two court filings by defense lawyers.

The filings do not reveal the contents of the conversations or whether the man, Sayfullo Saipov, 30, was overheard making threats or talking about an impending attack. Still, the filings suggested that Mr. Saipov was in touch with other people under F.B.I. surveillance.

The attack on Halloween last year was the deadliest terrorist attack in New York since Sept. 11, 2001. Mr. Saipov is accused of driving a pickup truck down a bike path along the Hudson River, killing eight people and injuring others. He then crashed into a school bus, ran down the highway waving a pellet gun and a paintball gun and shouted “God is great” in Arabic.

Mr. Saipov’s lawyers said in court papers that they had received a trove of materials from the government concerning “surreptitious F.B.I. surveillance of Mr. Saipov’s communications.” Those materials included “numerous audio recordings of conversations between Mr. Saipov and various targets of F.B.I. surveillance,” along with about 1,000 pages of translated summaries of the calls, which were largely in Uzbek, the lawyers said.