Sri Lankan immigration authorities have deport over 600 people for alleged visa violations since the Easter Sunday bombings.
The figure includes those authorities say were working as Islamic preachers despite entering the country on a tourist visa.
An Immigration Department official reportedly told the Sunday Times, "at least 200 foreigners were in involved in Islamic preaching in Sri Lanka".
Their visas were issued on the recommendations of the Muslim Affairs Ministry, the official added.
Visas were issued by the Immigration Department following security clearance by the Ministry of Defence.