Tapaitau trained with the FBI in the United States before studying law at the University of Auckland.[1] He served as Police Commissioner[1] before entering politics. He was elected to the Parliament of the Cook Islands at the 1994 election, representing the seat of Penrhyn for the Cook Islands Party. He served as a Minister in the government of Geoffrey Henry, holding the portfolios of marine resources, broadcasting, police and attorney-general. In 1997, he was accused by opposition MP Norman George of misappropriating government materials to build a house in his electorate, but was cleared.[2] He was appointed to the short-lived Cabinet of Joe Williams,[3] but ousted when Terepai Maoate took power.[4] In June 2000 he left the Cook islands party and switched his support to the government.[5] In February 2002 he was appointed to Maoate's Cabinet, but was ousted just days later when the Maoate government lost a confidence motion to Robert Woonton.[1]
In 2002, he was disqualified from Parliament, precipitating a by-election, which he lost.[6] He stood again for the seat as a Democratic Party candidate at the 2004 election, but was unsuccessful.[7] Despite holding the position of deputy leader of the Democratic Party, he did not contest the 2006 election.
In October 2006, he was appointed High Commissioner to New Zealand,[8] a position he held until 2010.[1] In August 2007 he was replaced as Deputy Leader by Wilkie Rasmussen.[9]