In September last year the Turnbull Government reached agreement with Slater and Gordon to hand over $70M of taxpayers money to compensate unlawful boat arrivals for being detained at Manus Island.

Today, Slater and Gordon wants the world to know that it's handed out the last of our $70M - and that it was a difficult job to get rid of all the cash.

Here's 9 news with their report.

The full $70 million from a class action settlement has been paid out to 1700 former Manus Island detainees.

Payments under Australia's largest human rights class action settlement have been completed, three-and-a-half years after the legal action began.

Slater and Gordon principal lawyer Andrew Baker said it was one of the most complex settlement distributions in the firm's 25-year history of class actions in Australia.

The full $70 million amount plus all interest earned in the settlement account has been paid out to the 1693 class action group members who registered to participate in the scheme.

The payments made across 39 countries were completed in under six months, Mr Baker noted.

"These figures and timeframes are the best we have seen for an action of this size and type, especially considering the added complexities of paying the funds to as diverse a group as this in so many different locations," he said.

"But there were simply no other options when the circumstances being faced by this group of people were taken into account."

The Slater and Gordon distribution team's communications with group members speaking 22 different languages involved more than 125,000 Whats App and text messages, 52,000 emails and 3000 phone calls.

The Australian government and operators of the now-closed offshore immigration detention centre settled the class action a year ago without any admission of liability.

The individuals received between a few thousand dollars and almost $100,000 each, mainly for false imprisonment after a Papua New Guinea court ruled their detention on Manus was illegal.

A final hearing over the settlement distribution will be held in the Victorian Supreme Court on Wednesday.