French authorities said Djamel Beghal, 35, a French-Algerian, is said to have confessed during interrogation last month that he visited mosques in London and Leicester to recruit new members to Bin Laden's al-Quaida network.
He is also said to have admitted to being involved in a bin Laden-backed plot to blow up the US embassy in Paris.
Suspects believed to be plotting attacks in Europe, including the US embassy in Paris, Nato headquarters in Belgium and the European parliament in Brussels - have all been arrested in Britain, France, the Netherlands, Belgium and Spain.
Terrorist acts denied
Despite his earlier confessions, Djamel Beghal changed his story while under interrogation in Paris on Tuesday, withdrawing many of his earlier statements about the plot.
His lawyer, Fabrice Dubest, said: "He formally denies having received the mission of preparing terrorist acts in France against the US embassy."
Another French-Algerian, Kamel Daoudi, 27, was arrested in Leicester last week and extradited to France on Saturday.
He was thought to have fled Paris for Leicester following the arrest of seven embassy plot suspects in Paris on 21 September.
Two other men arrested with Kamel Daoudi under the Terrorism Act in Leicester have been handed over by police to the Immigration Service.
Anti terrorist officers have released without charge a 36-year-old man arrested at Gatwick airport last Friday.
Islamic cleric inquiry
The man, believed to be an Arab, was travelling from the Middle East to the US.
It is suggested he was attempting to follow the same route to the US as 11 of the 19 suicide hijackers who attacked New York and Washington.
But a Sussex Police spokesman said: "The man arrested under the Prevention of Terrorism Act has been released without charge and is now with the immigration authorities."
Officers in London are continuing to question a 43-year-old man, who was
arrested on Tuesday over whether he raised funds for the extremist group Islamic
Jihad, which is banned in Britain.
They obtained a 48-hour extension to continue questioning him.
Police are also widening their investigation into the activities of a British-based Islamic cleric who issued a fatwa against Pakistan's President, General Pervez Musharraf, over his support for America.
They are investigating whether he has breached the Terrorism Act by inciting or supporting terrorism abroad or has incited racial hatred, an offence under the Public Order Act.