An Egyptian chemist freed Tuesday after three weeks in custody for questioning about deadly bombings in London said he casually knew two of the attackers.

After his release, Magdy Nashar told reporters outside his home that he had nothing to do with the July 7 transit attacks, which killed 52 people and the four presumed bombers.

"I am innocent, my country is innocent," said Nashar, who had been studying at the University of Leeds in northern England.

He was detained in Cairo in mid-July after British investigators told Egyptian authorities that they suspected he may have had links to some of the July 7 attackers. Three of the presumed bombers were from Leeds.

The Interior Ministry said Nashar was freed after authorities found no evidence against him. London police had no comment on the release.

The chemist said his release was held up by the failed attacks in London on July 21 and the deadly bombings at the Egyptian Red Sea resort of Sharm el-Sheikh two days later.

"I want to go back again. But I am afraid, honestly, I am afraid. Propaganda against me made people think I am terrorist," Nashar said. "My picture is everywhere. Some said I am the first man. The most-wanted man. If I walk down the street and someone recognizes me, he might kill me."

The 33-year-old chemist said he met one of the presumed bombers, Jamaican-born Germaine Lindsay, in Leeds during Ramadan, the Muslim month of fasting, which was in October and November last year.

Nashar said that in June, Lindsay asked for help finding a place to live in Leeds, saying he wanted to move there from London with his wife and child.

He said he located quarters for them through his landlord and was introduced by Lindsay to a man called Mohammed, who turned out to be Hasib Hussain, another of the presumed bombers.

Nashar said he helped Lindsay because he was a "new convert" to Islam. "He was very kind and very nice."

At the time of the bombings, British media reported that traces of TATP, a highly volatile substance, were found in Nashar's apartment in Leeds. Those reports were never confirmed.

Magdy Nashar was released after three weeks. Egyptian authorities found he was not linked to the July 7 attacks.