Police investigating the death of Waihi Beach woman Kelly Ann Sinclair are waiting for toxicology results before determining her cause of death.

The 25-year-old's body was found in her crashed Audi in a paddock off State Highway 2, south of Katikati, last Wednesday.

Kelly Ann Sinclair was found in her crashed Audi on Wednesday.

Kelly was reported missing by family on Tuesday after last being seen leaving a friend's house in Katikati on Sunday, April 6.

Police say she was heading to a friend's place in Mount Maunganui but never arrived.

Kelly's blue 1997 Audi A3 was towed from the paddock on Wednesday evening.

Acting Senior Sergeant Wayne Hunter says officers are waiting for toxicology results before making a determination of the crash and Kelly's death.

'Kelly's vehicle was the only one involved in the crash.”

Initial police investigations are that the Audi was travelling north towards Katikati when it crossed the centreline on a left hand bend and crashed off SH2.

'If people have information about Kelly and or her car before the crash can they please contact police.”

People can call the Tauranga Police Station on 577 4300 with information or alternatively, information can be left anonymously via the Crimestoppers 0800 555 111 line.