* Case involves alleged poisoning, coup d'etat
* France refuses to extradite suspect-source
By Samuel Elijah
COTONOU, Dec 5 (Reuters) - A judge presiding over a case involving an alleged attempt to poison and overthrow the Benin president is seeking asylum in the United States, the head of Benin's magistrates' union said.
Citing threats to his life, Judge Angelo Houssou fled the small West African country before a ruling in Paris on Benin's request to extradite cotton magnate Patrice Talon, accused of ordering the poisoning of President Boni Yayi in 2012 and later plotting a coup.
France has denied the request to extradite him for lack of evidence, a Paris judicial source said on Thursday. Talon has always denied the charges and judge Houssou dismissed them in May, along with those against Yayi's niece and personal doctor.
"The judge Angelo Houssou called me this evening and said he was being kept in the detention zone of the JFK airport in New York," magistrates union chief Michel Adjaka said.
"Pursuant to federal regulation and policy, we do not confirm, deny or otherwise comment on whether an individual has applied for or been granted asylum," the U.S. State Department said.
Benin, a small West African cotton producer, has enjoyed political stability and multi-party politics since the 1990s.
Houssou, who was stopped by Benin officials while crossing into Nigeria in May, escaped late last week by crossing neighbouring Togo and then boarding a New York-bound flight from Ghana, according to Adjaka.
Benin filed a legal complaint against him for "illegal attempt to leave national territory" after the attempted crossing into Nigeria, and he frequently complained of threats to his life.
"I am surrounded by military personnel and police in my home...my life is in danger," he told journalists last week.
Yayi, a former banker, became president in 2006 and survived an assassination attempt in 2007 when gunmen ambushed his convoy. He won re-election as president under disputed circumstances in March 2011. (Reporting by Samuel Elijah and Yves Clarisse; Additional reporting by Lesley Wroughton; Writing by Emma Farge; Editing by Bate Felix and Mark Heinrich)