Appointed head of the 400-strong Tongan police force last September, the 59-year-old said the sinking of the inter-island ferry Princess Ashika had devastated the maritime nation.
"It is a stressful situation for all involved," Cmdr Kelley, who is co-ordinating the search for survivors, said.
Cmdr Kelley said he had just been at the airport to see some of the survivors and a body return to Nuku'alofa.
"There was a substantial number of people to meet them, including the royal highness. At this stage, we are taking statements. We are not speculating about the cause at this stage," Cmdr Kelley said.
The support from New Zealand and Australia to help search for the remaining 62 bodies was invaluable.
"This is a major operation." he said.
Cmdr Kelley, who retired from the New Zealand Police last year after 42 years' service, said "without a shadow of a doubt" the ferry sinking was the biggest tragedy he had faced in the line of duty.
Raised in Waikouaiti, Mr Kelley said the ferry sinking made him recall the time when he was a young police cadet in Wellington and was placed on standby during the sinking of Wahine.
The sinking of Princess Ashika had hit the "religious community hard. It is a very emotional time."
