A she-bomber planned to blow up British Airways Flight 223 over Washington with plastic explosives hidden inside her body, a chilling new report says.

U.S. security services told Scotland Yard that the woman - almost certainly linked to al Qaeda - planned to hide 8 to 12 ounces of the material tucked inside her reproductive region, London's Mirror newspaper reported.

When the flight was over the nation's capital, the bomber would go to the bathroom, remove the explosives and detonate a blast that would blow the aircraft out of the skies.

A Homeland Security official said he was unaware of a specific threat of a female suicide bomber who would hide explosives in her body.

But he added, "We've had concerns about IEDs" - improvised explosives devices.

As a result, airport security screeners check for women wearing loose clothing and other signs the official declined to talk about.

"Smuggling a bomb onto a plane by this method is one of our worst nightmares," a senior Scotland Yard source told the newspaper. "If you do not have specific information about the suspect, it would be impossible to carry out an intimate body search of every female passenger."