Kara Hurring and her daughter Leena are missing in China with Westpac's $3.8 million. Photo / Supplied

Kara Hurring and her daughter Leena are missing in China with Westpac's $3.8 million. Photo / Supplied

Bank-loan runaways Leo Gao and Kara Hurring will most likely face charges relating to access and use of a computer, but not theft.

Inquiry head Detective Senior Sergeant David Harvey said yesterday a theft charge would not be applicable as the couple had not physically handled the money involved.

If a conviction was secured, police would seek reparation for the amount mistakenly paid into Gao's account.

He urged them to come home soon before all the money was spent.

"This pair still have families in New Zealand and at some stage they may want to return to see them.

"I would suggest they take the opportunity to return to resolve this matter before the outstanding sum is spent."

Gao and Hurring fled Rotorua with $3.8 million three weeks ago after Westpac put $10 million into Gao's account.

The bank was able to recover the remaining amount, but the couple are believed to be hiding in Hong Kong.

Law professor Warren Brookbanks, of Auckland University, said last night that drafting criminal charges could be difficult.

Because the bank had, in effect, handed over the money, albeit by mistake, "it can't be pursued as a simple case of theft".

And to prove fraud usually required an element of false pretence or false representation, and no evidence of those had been reported.

Mr Harvey also said yesterday that police were preparing a formal request to the Chinese Government for assistance.

"The fact we are taking this step shows how seriously we are taking this investigation."

New Zealand has a mutual assistance treaty with China and Hong Kong under which police can apply for help on criminal matters.

Police also confirmed the identities of the runaways as 29-year-old Leo Gao and 30-year-old Kara Mary Jo Hurring (also known by the surname Yang) and said a family member who had been travelling with them had returned to New Zealand.

Mr Harvey would not name the person, but at lunchtime yesterday Aroha Hurring - sister of Kara - arrived at Auckland Airport, where she was met by a team of detectives.