The teenage couple then returned to the hotel and told the staff that Mrs Mack would settle the bill when she checked out later.
The Mail Online reported that they had asked for a safety deposit box to be opened and its contents given to them. It is believed the box had Mrs Mack's jewellery and their passports.
The staff refused because they said Mrs Mack had left instructions that only she should be allowed to open it, the report said.
The couple told the staff that they had more bags to collect, but they left the hotel through a back entrance and took a taxi to the airport.
The report quoted Denpasar police chief Djoko Hariutomo as saying that the couple approached immigration officials claiming they had lost their passports.
"They said they needed to get new passports in order to leave the country, but that was because the passports were locked inside the deposit box at the hotel," Mr Djoko was quoted as saying.
But when the immigration officials told them that lost passports have to be reported to the respective embassies, the duo left. They took a taxi to a hotel near the airport.
With an alert going out to all hotels and taxis, the police received a call from staff at the hotel.
The police raided a room at 8.30am on Wednesday, found the couple asleep and arrested them.
They were both subjected to blood and urine tests to check if they were on drugs, but officers said psychological tests and Heather's behaviour suggested she was "unpredictable".
This article was first published on August 16, 2014.
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