Train travel to China's heavily restricted Xinjiang province is being suspended indefinitely amid reports Muslim detainees are being transferred to prisons in far-flung provinces, fuelling speculation Beijing is attempting to disperse its mass political re-education program to obscure it from international view.

Key points: China has been "embarrassed" by global condemnation of its treatment of Uighurs

China has been "embarrassed" by global condemnation of its treatment of Uighurs Muslim detainees reportedly being sent thousands of kilometres from their homes in Xinjiang

Muslim detainees reportedly being sent thousands of kilometres from their homes in Xinjiang Beijing's approach to Uighur separatism becoming increasingly "radical"

Beijing has come under increased international scrutiny in recent months as the mass scale of its crackdown on ethnic Uighurs and other Muslim minorities living in north-western China became increasingly apparent.

Approximately 2 million people — including 1 million Uighur Muslims, or about 10 per cent of the Uighur population — have been detained in overcrowded camps across Xinjiang, according to a number of reports this year.

Human rights groups say detainees are held without charge in political re-education camps, while the rest of the population lives under onerous conditions, including unrelenting surveillance and severe movement restrictions.

Bordered by eight countries including the former Soviet Central Asian republics, Xinjiang is China's largest province. ( Supplied: Google Maps )

Reports have emerged that inmates are being transferred from their home province into neighbouring Gansu province as well as regions as distant as Heilongjiang, thousands of kilometres away on the opposite side of the country, with speculation China is using the tactic to more closely control the Muslim population as well as control the flow of information about alleged human rights abuses.

James Leibold, a China specialist at La Trobe University, said global condemnation has "embarrassed" Beijing, but authorities had no intention of heeding calls to allow independent human rights monitors into the autonomous region to assess the situation, instead moving detainees in secret.

"If anything, they plan to … make it more difficult to track what has become of Uighurs, Kazakhs and other Muslim minorities who have literally disappeared from their families into state custody," he said.

The secretive inmate transfers began earlier this year, according to a Radio Free Asia report, but reports of Beijing requisitioning the Xinjiang train station has observers concerned the operation is ramping up.

The reports come as the state-run People's Daily newspaper announced that ticket sales for passenger trains entering and leaving Xinjiang would be suspended from October 22 onwards, with no details about when services would recommence.

Sources in Gansu and neighbouring provinces have suggested that trains are still moving in and out of Xinjiang, but not with paying passengers, and a location called Li Xin farm in Gansu province has received increased attention as a location Muslim populations could be transferred to.

'Strategy of cultural and political re-engineering'

Kashgar, in the western province Xinjiang, is the country's Uighur heartland. ( ABC News: Matthew Carney )

Dr Leibold said the halting of train ticket sales, along with sudden highway closures, "suggest that in the last couple of months there has been an attempt to move large numbers of people".

Up to 300,000 detainees could be transported in the coming weeks, Radio Free Asia reported, with prisoners from other parts of the country being swapped into Xinjiang facilities.

"It's a significant event in terms of the logistics of it," David Brophy, a China researcher at the University of Sydney, told the ABC.

"And it's having an effect not just on transport in and out of Xinjiang, but around Xinjiang as well."

Dr Brophy said the reports that prisoners from elsewhere in China were being taken to Xinjiang indicated the policy change was more likely to be about controlling Muslim detainees than addressing overcrowding.

China has never officially acknowledged the existence of the camps, but maintains its tough line on Xinjiang is necessary to counter terrorism. The region is home to a long-running separatist movement.

In response to emailed questions from the ABC, the Chinese Embassy in Australia referred to the transcript of a Foreign Affairs Ministry press conference on September 20, where spokesman Geng Shuang said the "measures implemented in Xinjiang are meant to improve stability, development, solidarity and people's livelihood".

Beijing's approach to what the Chinese commentariat have dubbed the "virus of extremism" has become increasingly "radical", according to Dr Leibold.

"This strategy seems to be one of cultural and political re-engineering of the entire population," he said.

It constituted an attempt "to remould them in the form of Han-defined cultural and political norms", Dr Leibold added, referring to the Han Chinese majority.