( CNN) What happened to Otto Warmbier while “hes in” North Korean custody is a whodunit. And it’s likely to remain that style. Following his death on Monday, Warmbier’s parents Cindy and Fred asked the coroner not to perform an autopsy on their son.

“The family’s objection to an autopsy was honored, and merely an external exam was performed, ” the Hamilton County( Ohio) Coroner’s Office said in a statement Tuesday.

“No conclusions about the cause and style of Mr. Warmbier’s death have been drawn at this time, as there are additional medical record and imaging to review and people to interview, ” the statement said.