Ahmed, an Indian engineer, is seriously ill in hospital after being badly burned when a jeep was driven into an airport terminal building in Glasgow on June 30 and set on fire.
The attack came 36 hours after detectives in central London discovered two cars packed with fuel, gas tanks and nails. One was outside a busy bar.
Police believe the two incidents are linked and Gordon Brown, the British prime minister, said that al Qaeda could be behind the suspected bomb plots, which prompted authorities to raise their alert level to "critical", the highest category.
Last week British police charged Ahmed's brother Sabeel with failing to disclose information that could have prevented an act of terrorism.
Federal police in Australia have charged Mohammed Haneef, Sabeel's second cousin, with providing support to a terrorist organisation.
Asha, who was born in Saudi Arabia, qualified as a doctor in Jordan in 2004 and came to Britain later that year to study neurosurgery at a hospital in central England.
He was arrested by police hours after the attempted attack in Glasgow and is due to appear in court in London on Friday.