The 29 year-old has been a regular member of the Tongan sevens team for the past 10 years. He also played rugby for Penrith in Australia and for the past few months for CSM Olimpia Bucharest in Romania.
Okati most recently captained Tonga at the Oceania Sevens tournament in Fiji in November.
Tongan Rugby Union interim chief executive Fe'ao Vunipola says the Board of directors will make a presentation to Okati's widow and his family - including cultural gifts and a financial contribution.
