TUNIS (Reuters) - For the friends and family of Chiheb Esseghaier, the news that the Tunisian-born student had been arrested over an alleged al Qaeda-backed plot in Canada came as a major surprise given his mission to save lives as a medical researcher.
His parents insisted he was innocent, saying he sent home money to help the disadvantaged. His friends in the Tunisian capital remembered him as an ordinary student, certainly no Islamist extremist, but perhaps somewhat naive and easily led.
Their recollections are not of the kind of young man who would go on to face charges in a distant country of conspiracy to murder and working with a terrorist group.
Esseghaier has been a doctoral student since 2010 at the INRS institute near Montreal where he is researching the use of nanotechnology to detect cancer and other diseases.
When he appeared in court in Canada this week, he had a thick black beard, something his friends at home in Tunis do not remember him ever having.
In the Gazella district about 15 km (9 miles) from the capital, the house where Esseghaier was born has been temporarily abandoned by his family, seeking relief from curious journalists.
His parents on Thursday described their son as an "angel", and suggested that his arrest was somehow prompted by the fallout from the Boston Marathon bombings this month.
Chiheb's father, Mohamed Rashad Esseghaier, was shocked by the news the eldest of his three sons had been arrested, and was sure of his innocence when he spoke to Reuters by telephone.
"My son is a human being and could not kill an ant. He is the victim of a security crackdown carried out by Canada against religious people to convince people that the Boston incident will not be repeated in Canada."
"My son is a genius. He has accomplished excellent medical research. He attended seminars in New York. I am proud of him," the father said.
His son had sent money home and asked that it be distributed among the unemployed and those who had played their part in the Tunisian revolution, the first uprising in the Arab Spring, two years ago.
Referring to Esseghaier's medical research, his father said: "Someone who helps people to live cannot think of ending the lives of others."
Esseghaier's father called on the Tunisian authorities to back him in maintaining his son's innocence of the charges against him.
Raoudha, his mother, said her son had become more religious in recent months, visiting the mosque. But she did not see that this was a problem and remained confident of his innocence.
"My son is the flower of Tunisia and I'm proud of him," she said.
Esseghaier's fellow students in Tunis recalled a suggestible young man who showed no signs of Islamist fervor.
"He was an ordinary student ... There was no sign of religious militancy," said Meriam Sassi, one of Esseghaier's friends.
"But it was easy to influence him; he has a weak personality," she told Reuters. "He could not differentiate between the truth and a joke."
She recalled that he was certainly not a loner, but he did display a certain innocence when it came to interacting with young women.
"He did not know the difference between a condom and a packet of chewing gum," she said, adding that she was in shock after hearing that Esseghaier had been arrested.
Samir Galouli a 29-year-old engineer who studied with Esseghaier at the INSAT institute, a modern scientific and technical college in Tunis with links to France, also found it hard to believe the news from Canada; he said he remembered his friend as a fan of Turkish and Western music.
"I am shocked by this news," Galouli said in a telephone interview. "He was an excellent student of biology.
"He was a playful spirit, but he was a weak personality and it was easy to influence him."
Esseghaier appeared in court on Wednesday and rejected the authority of Canadian law to judge him, saying the criminal code was not the holy book.
He and another suspect, Raed Jaser, are charged with plotting to derail a train, and U.S. security sources say they sought to attack at a bridge near the U.S.-Canada border.
(Reporting By Tarek Amara; Editing by Giles Elgood)