A former US Navy sailor, allegedly linked to two Tooting terror suspects who prosecutors believe were plotting to kill American military personnel, has been arrested and charged in America.

The authorities believe Hassan Abujihaad, 31, was the inside man for Babar Ahmad and Syed Talha Ahsan, supplying them with classified naval information which highlighted the perceived vulnerability of a group of battle ships, especially to small weapons such as rocket-propelled grenades.

Ahmad, a 32-year-old computer expert, and Ahsan, a 27-year-old former Franciscan Primary School pupil, both from Tooting, are currently fighting extradition to America, where they are wanted on several charges relating to terrorism.

Abujihaad, formerly known as Paul Hall, has until now been the missing link in the case against the two Tooting suspects.

All three are wanted in Connecticut, where a company hosted London-based websites and email accounts run by Azzamm Publications, an organisation which promoted violent jihad and was allegedly headed by Ahmad between 1997 and 2002.

According to court records, police found a disc at Ahmad's Tooting home, in 2003, which included secret information detailing the movements of a US Navy battle group from California to the Middle East in Spring 2001.

Further forensic checks determined Ahsan, of Franciscan Road, allegedly accessed and modified the file.

The authorities later linked the Tooting pair to Abujihaad, who at that time was on active service as a signalman second class aboard the USS Benfold, part of the battle group engaged in missions against al-Qa'eda.

Prosecutors claim they have evidence of emails between Azzamm Publications and Abujihaad, with his navy email address being found in Tooting.

In one of the emails allegedly sent by Abujihaad, who was discharged from the navy in 2002, he praised an October 2000 al-Qa'eda attack on an American warship in Yemen, which killed 17 sailors, as a "martyrdom operation" and advised such tactics were working and taking their toll.

According to US Attorney for Connecticut Kevin O'Connor, Azzamm Publications replied with an email encouraging him to "keep up the psychological warfare".

It is also believed Abujihaad, who faces 25 years in jail if convicted, bought videos from Azzamm and donated money. Mr O'Connor further alleges that, after learning of Ahmad's arrest in 2004, the former sailor destroyed Azzamm videos and deleted computer files.

During his arrest, when he was trying to buy two assault rifles in a sting operation, he was recorded admitting to sending the emails and later destroying materials.

Ahsan is currently awaiting the decision of his extradition hearing, while Ahmad, who has been held in Belmarsh Prison for two-and-a-half years without charge, waits to hear whether the House of Lords will hear his appeal against extradition.