A post-mortem has reportedly failed to find the cause of Cilla Black's death.
The late singer and entertainer died at her Spanish holiday home on Sunday, aged 72.
Spanish sources close to the investigation quoted by The Telegraph said her death was "non-suspicious" and a post-mortem had proved "inconclusive".
Samples will be taken to a lab in Seville for further testing, which the source said was "standard practice".
Black was on holiday with her son Estepona, in Spain, at the time. A report by The Sun claimed Black may have walked from an air-conditioned room in to midday heat, with the change in temperature causing her to become dizzy and fall.
It quoted a source close to the investigation as saying medical examiners would look at marks on her arm and elbow that could be linked to a fall.
Black's publicist could not be reached for comment.
