An Iranian general killed in a massive explosion at a munitions base outside the capital on November 12 was working on an intercontinental missile, his brother told a government-run newspaper.

General Hassan Tehrani Moqaddam died while working on a "project related to intercontinental ballistic missiles," Mohammad Tehrani Moqaddam, a Revolutionary Guards commander, told Saturday's Iran newspaper.

The Guards have said the huge blast -- which also killed at least 35 other Guards members at the base, according to media reports -- was an accident, implicitly rejecting Western media speculation it might have been an covert Israeli or US attack.

Mohammad Tehrani Moqaddam was quoted as saying that his brother's missile project "was in its final phase" and was "completely hi-tech and secret." He said he believed the project would still be successfully completed.

Hassan Tehrani Moqaddam was known as a key figure in the Revolutionary Guards' ballistic missile programme.

Officials in Tehran said he founded the programme after becoming an artillery specialist in the 1980s, during the Iraq-Iran war.

The chief of staff of Iran's armed forces, General Hassan Firouzabadi, said last Wednesday the base was being used in the production of an unspecified "experimental product" that could be used against the United States or Israel.

Firouzabadi said the development of the project had been delayed by "two weeks" because of the blast.