An Egyptian biochemist arrested in Cairo in connection with the London subway and bus bombings taught at a British university after taking graduate courses in North Carolina.
Magdy el-Nashar (search), 33, has denied any role in the attacks during questioning by Egyptian authorities, the Interior Ministry said in a statement.
A government official said el-Nashar was detained in Cairo between July 7, when the bombings occurred, and Wednesday.
U.S., British and Egyptian officials had been in contact concerning el-Nashar following the attacks, the official said.
The official spoke on condition of anonymity because he was giving information not in the official ministry announcement.
The ministry said el-Nashar came to Egypt from London on vacation and intended to return to Britain to continue his studies.
"El-Nashar denied having any relation with the latest events in London. He pointed out (to questioners) that all his belongings remained in his apartment in Britain," the ministry statement said.
The head of the Cairo research center that sponsored el-Nashar's studies said he arrived in the Egyptian capital two weeks ago.
British and FBI officials were looking for el-Nashar, who recently had been teaching chemistry at Leeds University (search), north of London. The Times of London said el-Nashar was believed to have rented one of the homes police searched in Leeds in a series of raids Tuesday.
The four other men also believed to have been involved in the bombings all had connections to the Leeds area.
Neighbors reported el-Nashar recently left Britain, saying he had a visa problem, the newspaper said.
Leeds University said el-Nashar arrived in October 2000 to do biochemical research, sponsored by the National Research Center in Cairo, Egypt. It said he earned a doctorate on May 6.
The head of the research center said el-Nashar returned to Egypt two weeks ago, turned in his Ph.D. thesis to the center's Chemistry Department and spent a week there with colleagues.
A week ago, el-Nashar told colleagues at the center he was going on vacation for 45 days, the center's president, Dr. Hany el-Nazer, told The Associated Press.
FBI agents in Raleigh, N.C., had joined the search for el-Nashar, a former graduate student at North Carolina State University.
University spokesman Keith Nichols said a person named el-Nashar studied at North Carolina State as a graduate student in chemical engineering for a semester beginning in January 2000. Nichols said the school has gathered records in anticipation of being contacted by the FBI.