A twelfth person was charged last night over the alleged airliner bomb plot, police said.
Umair Hussain was charged under the Terrorism Act 2000 with failing to disclose information about his brother Nabeel Hussain.
The alleged offence is contrary to section 38b (1) (a) and (2) of the Act.
On Tuesday, 11 people were remanded in custody over the alleged plot at City of Westminster Magistrates Court.
Umair Hussain will appear at the same court today.
Scotland Yard said: "Officers from the Metropolitan Police Anti-Terrorist Branch have this evening charged a man under the Terrorism Act 2000 following the anti-terrorist operation overnight on 9/10 August 2006.
"Umair Hussain is charged: On diverse days between September 23 2005 and August 10 2006 within the jurisdiction of the Central Criminal Court had information which he knew or believed might be of material assistance in preventing the commission of another person, namely Nabeel Hussain, of an act of terrorism and failed to disclose it as soon as reasonably practicable. Contrary to Section 38B (1) (a) and (2) of the Terrorism Act 2000."
Eight other people remain in custody and detectives have until next Wednesday to question them.