Phra Dhammajayo fainted while being carried into a van, meaning he could not report to Khlong Luang police at 2.30pm on Thursday as scheduled, his lawyer said.
The Department of Special Investigation (DSI) earlier set the deadline for the abbot of Wat Dhammakaya to hear money-laundering charges against him on Thursday.
Samphan Sermcheep, his lawyer, informed police around noon on Thursday that Phra Dhammajayo would show up at 2.30pm at Khlong Luang police station in Pathum Thani, a kilometre away from the temple.
The letter said the abbot could not go to the DSI, whose office is at the Government Complex in Bangkok, and his doctors had advised him against travelling that far since there was a fatal risk of blood clot in the lung.
It also said many of his disciples might follow him to the DSI, causing disturbances there.
It suggested Phra Dhammajayo report himself at the Khlong Luang police station opposite the temple instead.
Hundreds of monks from temple walked to the station ahead of the time. But when the time came, his lawyer said he was suddenly taken ill while being taken into a van to the police station.
He said the abbot became dizzy and fainted while being transported into the vehicle.
The lawyer asked the DSI and police to defer the deadline and said the temple would issue a statement at 3pm after the abbot's doctors meet to discuss his condition.
The investigators said they would meet on Friday to discuss steps for his arrest, said Kachornsak Putthanuparb, special public prosecutor, in a briefing held after Phra Dhammajayo failed to show up.
“We have complied with the law and given the monk opportunities and due respect the best we could. We’ll meet tomorrow to determine steps for the arrest. But a helicopter won’t be used,” he said.