His father, Allan Sinclair, said Paul rang home in the middle of the night to tell his parents of the accident.
"He said he was all right, we can only go by what he says, but he's got a fractured back so he's being flown to Darwin to be operated on," said Sinclair.
"He's in a fair bit of pain, he sounds pretty shaken up."
Sinclair added that after the engine exploded, his son and Love were "flown about".
Paul Sinclair was put on a surf board so that he wouldn't move around too much.
"They went to the Lombok public hospital and no-one could speak English so they went to a private hospital and had an MRI scan which revealed some fractures."
The Ministry of Foreign Affairs and Trade said it was aware of the incident.
"The NZ Embassy in Jakarta is following up on reports a NZ citizen may have been injured in the ferry fire," a spokesperson said.
There are currently 331 New Zealanders registered as travelling in Indonesia.
Speaking from Lombok Hospital, Ms Love told NewstalkZB Paul was tired and sore but could move all his limbs.
He had a broken back, possibly a broken ankle, and burns to his legs, she said.
The couple would be flying to Darwin shortly, she said.