He called one of them “very kind and very nice”.
After his release, Magdy el-Nashar told reporters that he had nothing to do with the attacks, which killed 52 people and the four bombers.
“I am very happy for my innocence and Egypt’s innocence, my first country, but sad for what happened in Britain, my second country,” said Mr el-Nashar, who had studied at the University of Leeds since 2000, earning a doctorate in biochemistry in April.
He was detained in Cairo on July 14 after Britain notified Egyptian authorities that they suspected he may have had links to some of the attackers, three of whom were from Leeds.
The 33-year-old said he met one of the bombers, Jamaican-born Jermaine Lindsay, in Leeds last November and that Lindsay introduced him to Hasib Hussain, another of the July 7 bombers.
Mr el-Nashar, a Muslim, said he helped Lindsay find a place to live because he was a “new convert (to Islam). He was very kind and very nice”.
Mr el-Nashar said Islam was not an issue in the attacks, and he called the suicide bombers “young, emotional and ignorant”.
Mr el-Nashar issued an appeal for governments to “stop oppressing people, killing and bombing people so that ignorant and emotional people don’t have an excuse for such activities”.
Mr el-Nashar called his detention “a nightmare”, but said he was not mistreated and only questioned by Egyptian authorities.
The Interior Ministry said no evidence was found against Mr el-Nashar.