Sanjar Umarov was arrested late on 22 October in the capital Tashkent on charges of economic crimes. Since his arrest, four other members of the group have been detained.
Nodira Hidoyatova, a coordinator for the group, says that police have also raided the group's offices in Tashkent, confiscating materials.
The Sunshine Uzbekistan coalition has been calling for the sacking of the government since a severe military crackdown on demonstrators in the eastern city of Andijon earlier this year.
(with AFP)