"This book is the proof," he said in Persian through a translator. "It's like a lab report." He said that by the month before the American Presidential election in November 1980, many in Iran's ruling circles were openly discussing the fact that a deal had been made between the Reagan campaign team and some Iranian religious leaders in which the hostages' release would be delayed until after the election so as to prevent President Carter's re-election.

In exchange, Iran was to receive arms from the Reagan Administration. Mr. Bani-Sadr does not have firsthand knowledge of the arrangement, he said, because the mullahs who consummated the deal were his political rivals and were simultaneously plotting to remove him from office.

Reagan campaign officials have strenuously denied that any such deal ever occurred. The persistent but unproven allegations were revived with the publication last month of an Op-Ed page article in The New York Times by Gary Sick, who was a staff member of the National Security Council under President Carter and who was involved in the hostage situation.

Mr. Sick, who now teaches at Columbia University, wrote that he now believed such a deal may have been initiated in July 1980 in a hotel meeting in Madrid between William J. Casey, the Reagan campaign chairman, and Hojatolislam Mehdi Karrubi, a cleric close to Ayatollah Ruhollah Khomeini, the Iranian revolutionary leader.

Mr. Sick said he was less convinced of charges that George Bush, then the Vice-Presidential candidate, attended meetings in Paris in October when the arrangment was consummated.