Kiribati's Marine Division says the formal search for passengers of the MV Butiraoi has been suspended after the ferry sank over two weeks ago.
A spokesman said the decision was made in conjunction with Rescue Coordination Centres in Fiji and New Zealand after covering a wide area both from the air and the sea.
The aerial search was suspended on Friday.
The spokesman said the three remaining search boats had now returned to Tarawa.
He said despite the suspension, Rescue Coordination Centres had been asked to continue broadcasting calls to all marine vessels in Kiribati waters to be on high alert for any survivors or debris from the ferry.
Yesterday two Kiribati Marine Department staff flew to Nonouti from where the ferry departed to gather more information.
Some of the seven survivors in Tarawa have already been interviewed about the accident.
The spokesman said he was compiling an investigative report, adding that it appeared the vessel may have become grounded twice before it sank.
He confirmed reports the MV Butiraoi was carrying up to 30 tonnes of coconuts in addition to more than 80 passengers.
The investigation is ongoing and expected to take more than a week.
Some of the survivors are reported to be still too traumatised to talk.
The Marine spokesman said once all the information had been gathered and the staff had returned from Nonouti he would report back to the Kiribati government.