Key Points:

An American agency operating an Antarctic base at which a scientist was fatally poisoned has denied that it did not co-operate fully with New Zealand investigators.

The United States National Science Foundation says it worked with the Christchurch coroner's office in probing the death of Australian astrophysicist Rodney David Marks.

Coroner Richard McElrea and Christchurch police were given the task of investigating because the body was initially flown to Christchurch.

Findings released by Mr McElrea this week found Dr Marks, 32, died of acute methanol poisoning while working at the Amundsen-Scott South Pole Station in May 2000.

It was possible he accidentally drank the solvent, but Mr McElrea could not rule out another person being involved.

In his report, Mr McElrea highlighted the difficulties police had faced in getting co-operation and reports from the National Science Foundation and an American contractor, Raytheon Polar Services.

But Washington NSF spokesman Peter West told the Herald the foundation had provided all information it was asked to.

"We understand the coroner takes issue with that, but we believe we did do everything required of us and beyond.

"The agency has voluntarily appeared at a hearing to answer the coroner's questions, has given extensive statements to the coroner, and has provided direct access to individuals who have personal knowledge of the circumstances surrounding Dr Marks' death."

Detective Senior Sergeant Grant Wormald told the inquest police were forced to find the names of 49 personnel at the base with Dr Marks on the internet, and got few responses to a questionnaire sent out to them.

Mr West said the NSF agreed to send out the questionnaire through Raytheon "to all persons at their last known addresses, and none were returned for bad addresses".

Mr Wormald understood a full investigation into the events at the base had been carried out, but he had been unable to access it.

But Mr West said this was a misconception. Only a medical review had been completed, and the results of this had been supplied to Mr McElrea.

Dr Marks' father, Paul Marks, said he was most hurt by the fact he had never heard from the NSF or Raytheon since his son's death. Mr West said he could not comment.