A British terror suspect ran websites that supported terrorists and urged Muslims to fight a holy war, his extradition hearing has heard.
Babar Ahmad, pictured in green, is fighting extradition to the US
Babar Ahmad, a 31-year-old computer expert from London, is accused of raising cash to support terrorism and faces extradition to the United States.
His lawyer said the UK's new extradition agreement with the US did not allow him to answer the charges.
But the Home Office insisted Mr Ahmad would be able to testify.
In claims dating back to 1997, the US government accuses Mr Ahmad of "conspiring to support terrorism", saying he "sought, invited and solicited contributions" via websites and emails.
John Hardy, appearing for the US State department, said two websites run by Mr Ahmad urged Muslims to use "every means at their disposal" to train for jihad, or holy war.
Mr Hardy told the hearing that one site, called azzam.com, which operated via service providers in the US from 1997 to 2003, included a posting reading: "Military training is an Islamic obligation, not an option."
It also carried a declaration of war against US forces in the Arabian peninsula from Osama bin Laden, Mr Hardy said.
Mr Ahmad's supporters gathered outside the court on Wednesday
He said another site carried an appeal for "tens of thousands" of gas masks and nuclear, chemical and biological warfare suits.
"This case in terms of evidence concerns publications on websites of the United States, which publications the government said sought and incited and solicited contributions to terrorist causes in Afghanistan and Chechnya," Mr Hardy told the hearing.
"[These] websites carried material inciting murder in both those countries and elsewhere and ... the government says, were established, operated and maintained by this defendant."
The US also claims Mr Ahmad had plans for one of its Navy battle groups in the Gulf, including comments on how ships were vulnerable to attack.
American lawyer Thomas Loflin, a defence witness, told the court he believed Mr Ahmad could face the death penalty or trial by military commission if extradited.
Edward Fitzgerald QC, appearing for Mr Ahmad, said: "There is a real risk that the defendant will suffer a flagrant denial of justice if returned."
Mr Ahmad's wife, Maryam Ahmad, told the BBC her husband would not get a fair trial in the US.
"We will fight to the end. We don't believe that he should be extradited, he's done nothing wrong and with time he will be proven innocent," she said.
If Mr Ahmad loses the hearing, expected to last two or three days, it will be up to the home secretary to decide if he should be sent to the United States.
Such an order would come under UK legislation which came into force in January 2004, which was designed to speed up the extradition of suspected terrorists.
Under the act there is no requirement for the US authorities to present a prima facie case, although UK authorities must do so in seeking extraditions from the US.
The Home Office said the case against Mr Ahmad is based on hard evidence being presented to the court.