A post mortem examination carried out on a four year-old girl who died last week has failed to find a cause of death.
Further tests will now be carried out on Alexa-Marie Quinn, who was from Hatfield.
Hertfordshire Police said it could take several weeks or even months before the results are known.
Alexa-Marie's father Carl Wheatley, 30, has been charged with her murder.
A father has appeared in court charged with murdering his 4-year-old daughter.
30-year-old Carl Wheatley is accused of killing Alexa-Marie Quinn at their home in Hatfield, Hertfordshire.
Wheatley appeared before magistrates at Hatfield and was remanded in custody to appear next at St Albans Crown Court on Tuesday 18th March.
A post mortem examination is expected to be carried out on Monday 17th March.
A man has been charged with the murder of his four year old daughter in Hatfield.
30-year-old Carl Wheatley is charged with murdering Alexa-Marie at their home address in Queen Bee Court.
Alexa-Marie died at Lister Hospital after police had been called to the house at 9.36am on March 12th.
A post mortem examination into the death of the 4-year old will take place on Monday 17th March.
Following the death of Alexa-Marie, the mothers side of the family released the following statement through Hertfordshire police.
"We are completely stunned and devastated that our beautiful little girl has been taken so suddenly. She was truly the most gentle, loving, happy and amazing little soul we had the pleasure of knowing. "
A1(M) Northbound closed due to accident investigation work between J1 M25 / A1 / A1081 St Albans Road / Bignells Corner (South Mimms) and J3 A414 / A1001 (St Albans / South Hatfield).
Reports of one lane blocked due to accident on A1(M) Northbound near J3 A414 / A1001 (St Albans / South Hatfield).
Police have confirmed that the body found in woodland near Hatfield on Sunday is that of 19-year-old Amelia Arnold.
The post mortem also confirmed that Amelia died as a result of head injuries.
Amelia's boyfriend, 22-year-old Jack Wall from Hadrians Walk in Stevenage, has been charged with murder.
Joseph Potter, 41, from Bletchley has also been charged with perverting the course of justice.
Police searching for a missing 19-year-old from Stevenage have found a body in woodland in Hatfield in Hertfordshire. Detectives believe it is the body of Amelia Arnold, who disappeared on Wednesday 7 November from the home she shared with her partner Jack Wall.
22-year-old Jack Wall of Hadrian's Walk in Stevenage has been arrested on suspicion of murder. A 41-year-old man has been charged with perverting the course of justice.
Police searching for a missing 19-year-old from Stevenage have found a body in woodland in Hatfield in Hertfordshire
Detectives believe it is the body of Amelia Arnold, who disappeared from her home in Hadrian's Walk in Stevenage on Wednesday 7 November.
Amelia's 22-year-old boyfriend Jack Wall, who lived with her at the property on Hadrian's Walk, has been arrested on suspicion of murder. A 41-year old man has appeared in court charged with perverting the course of justice.
Two men have pleaded not guilty to murdering a 24-year-old man in Hertfordshire in July.
Mikel Cela, 22, of Mountway Close in Welwyn Garden City and Amariloo Brami, 22, of Walnut Grove also in Welwyn Garden City, are accused of stabbing to death Darren Leonard at a flat on Northfield in Hatfield on Wednesday 11 July 2012. .
They appeared at St Albans Crown Court, where they both denied murder and conspiracy to rob. Both men were remanded in custody by Judge Stephen Gullick for a trial due to start on 7 January next year
Hatfield's Galleria shopping centre was surrounded by police vehicles and ambulances this afternoon after a woman fell from the roof.
Detectives were called at 1.40pm after reports from witnesses.
The woman died at the scene. Her family has been informed but the death is not thought to be suspicious.