Orifjon Oidin, a Turkish citizen, died on 8 December, more than a week after two unknown gunmen shot him in the head at his home.
Hidoyatova told AP that her husband was deported to Kazakhstan in May and killed because of her political activities.
She is a key coordinating figure in the Sunshine Uzbekistan opposition coalition and the head of the Free Farmers (Ozod Dehqonlar) opposition party.
Last month, the chairman of Sunshine Uzbekistan, Sanjar Umarov, was arrested on charges of embezzlement and tax evasion. Hidoyatova insisted the arrest was part of a government campaign to silence dissident voices.
The two have been vocal critics of the government crackdown of an uprising in the eastern city of Andijon in May, which left hundreds of people dead.