In September 1927, New Zealand appointed a Royal Commission to hear grievances against its Samoa administration. Despite hearing evidence from more than 150 witnesses, the Commission reported three months later in support of Administrator George Richardson's actions and policies. It also upheld his view that the Mau was inspired by a small group of local Europeans and their Samoan accomplices.
The Natives have no real grievances either against me or the Government, and I am confident of my ability to handle them once the influence of the European committee is removed.
Richardson in AJHR, 1928, Volume I, A-4B, Exhibit No. 52A
Key Europeans and 'half-castes', including Olaf Nelson, were deported to New Zealand in early 1928. Nelson continued resistance activities from Auckland. He petitioned the New Zealand government, and received support from the opposition Labour Party. In 1928 he published The Truth about Samoa. The Samoa Guardian newspaper, banned in Samoa, was re-established as the New Zealand Samoa Guardian.
That year Nelson presented a petition to the League of Nations in Geneva that outlined Samoan objections to New Zealand's administration. Of the 9300 adult Samoan men, 8000 had signed the petition. The Permanent Mandates Commission denied Nelson a hearing.
Meanwhile, the Mau intensified its campaign. In January 1928 Mau policemen, dressed in a uniform of a purple lavalava with a white stripe, began enforcing a sā - ban - on European stores in Apia. An observer described them as 'a genial smiling lot ... fraternising and laughing with the khaki clad police of the Administration.'
Richardson too stepped up measures. His request for two New Zealand-based Royal Navy warships to be sent to Samoa was granted in February 1928. Marines from HMS Dunedin and Diomede helped to enforce laws prohibiting Mau activities and made arrests.
The Mau remained ‘cheekily defiant'. When the arrest of some 400 Mau filled detention centres to breaking point, hundreds more gave themselves up. In a deeply humiliating experience for Richardson, the facilities were unable to cope and the prisoners were released. Richardson left Samoa in April 1928.
The new Administrator, Colonel Stephen Allen, believed that the Mau would gradually decline. In his view, it could be eradicated through firm police action. There were two violent clashes between police and Mau in 1928. The second, in November, saw Tupua Tamasese Lealofi III arrested and jailed in New Zealand for six months.
Throughout 1929, Allen believed the Mau was 'slowly dying', yet tensions simmered beneath the surface. They would erupt in violence on ‘Black Saturday'.