Talking to RFE/RL's Uzbek Service by phone today from the southern town of Jizzakh, Khamroev said security officers have been keeping a round-the-clock watch in front of his house for nine days, preventing him from going out.
"It's not only me, but almost all other human rights activists in Jizzakh [Region] are under house arrest, too," Khamroev said. "I believe the reason for this is that a European Union delegation is currently visiting Uzbekistan. I think that's why we're under permanent surveillance."
Uzbek authorities commonly put civic campaigners under house arrest when a foreign delegation travels to the country.
Khamroev told the independent information website uznews.net on December 13 that he was unable to go to Tashkent earlier this week to attend a reception given by the U.S. Embassy to mark Human Rights Day, on December 10.
Khamroev's son Ikhtiyor is currently serving a three-year jail sentence for hooliganism, a charge he denies.
Independent news reports this week indicated Ikhtiyor was unlikely to be freed under an amnesty that was recently announced to mark the 14th anniversary of the Uzbek constitution, although he should qualify for a pardon under the terms of the amnesty.