Bridging visas, requiring asylum seekers to find accommodation and seek work to pay their way as they wait for the outcome of refugee claims, are seen as a way to relieve pressure on the detention network and lower costs in the wake of the collapse of the Malaysia agreement.

But the Amnesty International spokesman Graham Thom, on an inspection tour of remote detention centres, has urged the government to speed up its bridging visa releases. ''It has started to happen, but it is very small numbers so far,'' he said.

There were 4179 boat arrivals in detention as at February 3, and 1438 people in community detention. The government pledged in November to release 100 a month on bridging visas.

The Red Cross, which has a two-year contract to run bridging visa support services, said it had taken three months to put staff in place to step up the program, but it was now ''on the launch pad''. Seventy-five visas had been issued in the past fortnight.

Of the arrivals released so far, most were finding accommodation with community groups or family, the Red Cross director of services, Michael Raper, said. But it was unlikely the asylum seekers would find work quickly and would instead access a payment of 89 per cent of the welfare benefit.

''Many of the people coming out now are likely to have been in detention for some time,'' Mr Raper said. ''They are not undamaged, and may be suffering from trauma and certainly are victims of long incarceration in immigration detention.''

If the government reduced mandatory detention to ''a matter of months'' the asylum seekers released would be ''less damaged so less in need of high-level assistance'', he said.

Dr Thom said the Curtin detention centre, in the remote West Australian desert, was ''a classic example of the cost of mandatory detention''.

''The logistics become extraordinarily problematic,'' he said. ''Only four of 15 phones are working for use by 1000 men. But how do you replace a broken phone? There are broken down washing machines … These little things break people down, too.''

The longest-serving asylum seeker at Curtin had been detained for 831 days, he said.