A British Muslim leader has said he does not believe an East Sussex Islamic school could be involved in any kind of extremism or violence.
Imam Abduljalil Sajid said he knew the Islamic school well
Imam Abduljalil Sajid, chairman of the UK Muslim Council for Religious and Racial Harmony, has visited the Jameah Islameah Islamic school several times.
The school, at Mark Cross, near Crowborough, is being searched as part of an anti-terror investigation.
A Sussex Police spokeswoman said no arrests had been made at the school.
"I was shocked to hear the police were interested in that building," said Imam Sajid, of Brighton Islamic Mission.
He said he had known Balil Patel, the owner of the Jameah Islameah school, since he was Imam of Balham Mosque in south London.
"So far as I know Imam Patel is not a man who has anything to do with extremism or violence," he said.
"He would oppose violence and terror and co-operate with the authorities 100%."
He said he had been involved with the school since Imam Patel bought the 100-room listed building in 54 acres of grounds.
It has previously been used as a ballet school and an orphanage but local people say it is in a dilapidated condition.
"I know it very well - I have been there five or six times," said Imam Sajid.
The school opened in September 2003 as an independent day school for Muslim boys aged from 11 to 16.
According to its Ofsted report last year, the school in Mark Cross had only nine boys on its roll, aged from 12 to 15, and inspectors found it failed to provide a satisfactory education.
Imam Sajid said he had attended "one or two" functions at the school.
"Imam Patel used to invite religious personalities from London and the southern counties, which I am very much involved in," he said.
"I heard that he also used to hire the place out for functions, conferences and various activities as a source of income."
"It is vast and he was unable to maintain it without the support of others."
The Jameah Islameah school is in a 19th Century listed building
Imam Sajid said he was concerned about the effect of the police activity on the local community and feared a backlash.
"My appeal to the community is not to be judgemental," he said. "Let the truth come out.
"Those who are criminally minded must be apprehended and we will support all the criminal investigation agencies, including the police."
Imam Patel has declined requests from the BBC to comment.
Speaking at the scene, the Sussex Police spokeswoman said forensic officers from both Sussex and the Metropolitan Police were involved in the operation at the school.
She said no arrests had been made at the school and that people living there at the time of the raid had been put up in alternative accommodation.
Seventeen residential addresses in London are also being searched and on Sunday night officers were given more time to question 14 men arrested in the city.
Twelve of the arrests - on suspicion of the commission, preparation or instigation of acts of terrorism - came at a Chinese restaurant in Borough.