The man was arrested in the Pakistani capital, Karachi, on arrival from Nairobi, on the day of the bombings, said Pakistan's Foreign Ministry on Sunday.

He is now being questioned by the Kenyan authorities and the FBI.

In a short statement, the investigating teams in Nairobi said that the man, who was returned to Kenya on Friday, is called Mohammed Saddiq Odeh, but is also known by two other names.

Pakistani Foreign Ministry spokesman Tariq Altaf: "He was carrying forged papers which were easily detectable"

The statement said the suspect has denied involvement in the embassy bombings.

Reports in Pakistani newspapers earlier said the man had confessed to being connected with the bombings and that he had identified others who had already crossed through Pakistan into Afghanistan.

An English-language newspaper in Pakistan, The News, reported that the suspect was heading towards Afghanistan when he was detained on suspicion of travelling on forged documents.

Prior to the detention of Mr Saddiq Odeh, police in Tanzania and Kenya had taken several people into custody for questioning.

But they were not considered to be prime suspects, and the Tanzanian authorities have released 12 of the 14 people they originally detained.

Albright's visit due

The US Secretary of State, Madeleine Albright, is due in Tanzania and Kenya on Tuesday.

Madeleine Albright: Mission to assure that US cares for Kenyan victims, too

She is expected to visit some of the injured as well as see the site of the blasts.

She is also expected to announce details of US aid to the two countries to help in the aftermath of the attacks.

The BBC correspondent in Nairobi, Cathy Jenkins, says the visit will be important if the US is to counter the perception held by some in Kenya that the Americans did not help them enough in the hours immediately after the bombings.

She says ordinary Kenyans who were at the scene trying to pull people from the rubble of a collapsed office block felt that the American soldiers who quickly cordoned off the damaged US embassy next door could have done more to help them.