Russia yesterday strongly denied that a cargo ship whose supposed seizure by pirates sparked an international mystery was secretly carrying sophisticated antiaircraft missiles bound for Iran.

Foreign Minister Sergei Lavrov dismissed reports that the Arctic Sea was carrying a batch of the Russian-made S-300 missiles when it was hijacked.

'Regarding the S-300s on board the Arctic Sea. this is absolutely untrue," Lavrov told reporters when asked about the report.

Separately. Russian investigators announced they had inspected the ship and found only its official cargo of timber.

'The cargo aboard the > ship, wood and sawn timber.

is being thoroughly inspected by investigators, as well as the ship itself a spokesman for the investigative committee of Russian prosecutors told AFP.

"Nothing besides the stated cargo has yet been found by investigators and forensic experts," he said, adding the ship was still at sea and the investigation would continue several more days.

The Arctic Sea, a Maltese-flagged vessel with a Russian crew, was hijacked near Sweden in late July before being recovered by the Russian navy in the Atlantic Ocean several weeks later.

The hijacking in a busy European shipping lane, the huge international effort to recover the ship, and the detention of its crewmen after they returned to Russia have all fuelled speculation about a secret cargo.

Officially the ship was carrying a load of timber Ivorth 1.7million dollars (1.16 million euros) from Finland to Algeria, bur speculation has raged that it was carrying weapons or even nuclear materials.

The ship is due to arrive within days at Russia's Black Sea port of Novorossiisk.

Lavrov said representatives of Malta, the flag government of the Arctic Sea, would be invited to take part in the investigation.

'Everything will be done transparently. I hope everyone will be convinced that the rumours you are referring to are absolutely groundless," Lavrov said in response to a reporter's question.

Meanwhile a Kremlin spokeswoman, Natalya Timakova. told reporters that any theories about what the Arctic Sea was carrying before the investigation was complete were "speculation."

This weekend the Sunday Times of London, citing Russian and Israeli sources, ^reported that Israel's Mossad intelligence service had learned the ship was carrying S-300s to Iran and worked with Moscow to stop the shipment.

According to the Sunday Times report. Israel learned that the ship had been loaded with weapons in Russia's Baltic Sea port of Kaliningrad by former military officers with links to criminal groups.

The newspaper said that Mossad, acting with the Moscow government's back ing, may have set up the hijacking in a bid to stop the shipment without causing Russia embarrassment.

Independent Russian defence analyst Pavel Felgenhauer dismissed the report, noting that S-300 batteries were large, heavy and complex systems that would be impossible to conceal in a cargo hold.

"Hypothetically, such a cargo ship could transport grenade launchers for Hezbollah or Hamas, Igla portable anti-aircraft missiles. something more compact than the S-300." Felgenhauer told AFP.

"At least this would not violate the laws of physics," added Felgenhauer, the defence columnist for Novaya Gazeta newspaper.

Time magazine has also quoted experts suggesting the vessel was carrying missiles destined for the Middle East.

Israeli President Shimon Peres visited Russia and held talks with his Russian counterpart Dmitry Medvedev on August 18, the day after Russia announced it had recaptured the Arctic Sea from pirates.

Following rhe talks, Peres said he had secured a promise from Medvedev that Russia would review its decision to sellS-300s to Iran.

Russia reportedly agreed to sell Iran the missiles several years ago. but Western countries and Israel fiercely opposed the deal as S-300s would greatly enhance Tehran's ability to protect against an air strike.

Eight suspects-- including Russians, Estonians and Latvians -- have been accused of hijacking the Arctic Sea and are now awaiting trial in Moscow on piracy and kidnappingcharges.