Intelligence agencies are studying a series of disturbing communications from Britain to well-known al-Qaeda terrorists sheltering in Saudi Arabia to see if it leads to another terror cell sheltering in Britain.

The messages from Saudi Arabia include transfers of cash to Britain. At least one of the failed July 21 bombers spent time in Saudi Arabia.

Scotland Yard made clear that their search for the support network and the “key logistical figures” behind the bombings will stretch worldwide and could take months.

It was the flight of Osman Hussain, also known as Hamdi Isaac, the suspected failed bomber, to join his brother in Rome that has led to revelations in Italy about his family’s alleged al-Qaeda links.

Anti-terror detectives in Rome disclosed yesterday how his brother, Remzi Hussain, was already under scrutiny in relation to al-Qaeda’s secret financial network.

Carlo De Stefano, the head of Italy’s counter-terror operations, said that Remzi Hussain, who lives in Rome, has been under surveillance since the attacks in the US on September 11, 2001.

He said that Remzi Hussain’s souvenir shop selling African artefacts on the Via Volturno near the city’s railway station is being investigated for its links to al-Barakaat, a finance company that has been banned by the US and most Western countries.

Al-Barakaat is the so-called al-Qaeda banking network that wires money around the globe. Investigators believe that it was such a system that was used to fund previous terror operations, including the attack last year on four trains in Madrid.

Terror financiers can shift cash to terror cells in any part of the world by simple money transfers that are hard to trace.

Last night police said that Remzi Hussain is under arrest for “falsifying documents”. It was to his flat in Rome that his brother fled after escaping Britain’s biggest manhunt on July 29. When police searched the flat on the Via Aurelia at Tor Pignatarra, a Rome suburb, they found records of air tickets used in “recent times” by Remzi Hussain to Dubai, Geneva, Zurich, Munich and Amsterdam.

In public, senior Italian officials said that Osman Hussain, who is thought to have tried to kill himself and others by blowing up a Tube train at Shepherd’s Bush, was part of “a rag tag” group and not linked to a major terror network.

Behind the scenes, however, Italian security forces have stepped up their investigations, fearing that their country may be the next to suffer a terrorist strike.

At the weekend Giuseppe Pisanu, the Interior Minister, said that Hussain, his brothers and friends formed part of a “tightly knit network” that posed a threat to Italy.

Alfredo Mantovano, Signor Pisanu’s deputy, said on Sunday that “the support network that Hamdi Isaac found in Italy confirms the presence in our country of autonomous Islamic cells that may represent a concrete threat”.

Police have dismissed claims that other members of the July 21 bombing attempts recently visited Rome, though they have asked for Scotland Yard’s help in trying to trace phone calls made from England.

Signor De Stefano told yesterday how intelligence services tracked Hussain across Europe by surveillance technology to eavesdrop on his mobile phone conversations.

Police and intelligence agencies listened as he desperately tried to find a way out of the net that was closing around him. They picked up Hussain speaking in an obscure Ethiopian dialect used on the border of Somalia and Eritrea, which encouraged them to believe they had the right man.

Hussain was tracked as he travelled by train through France to Italy but dumped his British SIM card and replaced it with an Italian one that was picked up by investigators in Rome.

He has allegedly told Rome police that his name is Hamdi Isaac, that he was born in Ethiopia and came to Italy with five brothers. Two remain in Italy, and both are under arrest; one emigrated to Canada while he and one other went to Britain in 1992 claiming that they were refugees from Somalia.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Looking for romance on the Blairs' love bus
• Children 'immersed in culture of violence'
• Hunt for black gold sweeps the country