"We deny having delivered the Fajr 5 to the Palestinian resistance. The aim of such accusations is to portray the resistance as weak whereas it is perfectly capable of producing the arms it needs," said Allaeddine Boroujerdi, head of parliament's foreign affairs committee.
Islamic Jihad claimed its militants fired a Fajr 5 which crashed into the sea off Tel Aviv on Thursday, in the first such attack on the heart of Israel since Saddam Hussin's Iraqi regime fired Scud missiles during the 1991 Gulf war.
Sirens went off in Tel Aviv again on Saturday for a third straight day, sending people scuttling for cover, a day after a rocket crashed into the Mediterranean near the city centre, AFP correspondents said.
The latest rocket was intercepted by Israel's Iron Dome defence system.
The armed wing of the Islamist Hamas movement which rules Gaza and which like Islamic Jihad is supported by Tehran, claimed the latest Fajr 5 fire.
The Fajr 5 rocket has a far greater range than the home-produced Qassam rockets normally used by Palestinian militants in Gaza to target Israel, but neither are very accurate, defence analysts say.
Fajr 5 rockets can be fired from the back of a 6x6 truck to hit targets up to 75 kilometres (46 miles) away. This compares to a range of between four and 13 kilometres for the Qassam rockets.