A suspected al Qaida terrorist charged over the 1998 attacks on embassies in east Africa that killed more than 200 people has died in custody days before his trial was to start in the United States.

Manhattan attorney Preet Bharara says in a court filing that Abu Anas al-Libi, also known as Nazih Abdul-Hamed al-Ruqai, died on Friday from sudden complications "arising out of his long-standing medical problems".

Al-Libi had pleaded not guilty to charges he conspired in the simultaneous attacks on embassies in Tanzania and Kenya that killed 224 people, including a dozen Americans. His family and former associates denied he was ever a member of al Qaida.

His trial was to begin on January 12 in Manhattan.

The US captured al-Libi during a raid in Tripoli in October 2013.

Today his wife, who asked to be identified as Um Abdullah, said the experience only worsened his ailments, including hepatitis C, leading to his death.

"I accuse the American government of kidnapping, mistreating, and killing an innocent man. He did nothing," Um Abdullah said.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.