Mr Burroughs said police were looking to establish whether his Mr Tiensch's death was related to a court case between him and his former employer.
"We're definitely looking into the possibility of it being related to the court case, but we're also not excluding other possibilities,'' he said.
In a lawsuit against the company, Mr Tiensch accused Plus SMS of fraud and wrongful dismissal, to which the company counterclaimed with allegations of fraud and blackmail of board members.
A US court last month awarded Mr Tiensch a $US430,000 settlement but the money remained in the custody of the court, with a hearing set down for Thursday over releasing the money to Mr Tiensch and his family.
Mr Burroughs said police had exchanged emails with Plus SMS, but New Zealand police were not yet involved in the investigation.
"We're working on the appropriate protocols to do that,'' he said.
Mr Burroughs said police were continuing to track down leads and talk to witnesses.
They had subpoenaed records related to other guests staying at the Holiday Inn Express in Port Aransas, where Mr Tiensch had been staying on a fishing trip until he was reported missing by his wife on September 11.
Police found his wallet and personal items untouched in his hotel room and his Range Rover in the parking lot.
An aerial search found his body on the remote island which was accessible only by air or boat.
Police are treating his death as homicide and have ruled out suicide.
Mr Tiensch joined Plus SMS in 2006, just months before the company declared it had made unrealistic statements and a Securities Commission investigation was launched.
He argued in court that the directors had persuaded him to mislead the public to inflate stock prices, and was ousted when he refused.
