A later memorial service will also be held

The service, strictly private at the request of her family, was held in High Wycombe, Buckinghamshire, Sadler's home town.

The service was to be followed by a cremation at Amersham Crematorium.

It is understood that the BBC's head of drama series, Mal Young, was to lead the tributes to the actress, who played nurse Sandy Harper in the popular series.

Her Holby City co-star Hugh Quarshie, who plays surgeon Ric Griffin, was to read a poem and her family asked that one of her favourite songs, Angels by Robbie Williams, be played.

Sadler, who was 22, died on 19 June four days after falling 40 feet (12 metres) from the balcony of a flat in Holland Park, west London.

A later memorial service is planned, although the date has yet to be announced.

George Calil played her on-screen boyfriend

Her on- and off-screen boyfriend, George Calil, will not face charges over the death after being arrested.

"The death is being regarded as non-suspicious," a Scotland Yard statement said.

Calil, 30, who played her drug-dealing partner in the show, described Sadler as "the love of my life".

Sadler was a fixture in Holby City as staff nurse Sandy Harper for three years. The show is watched by about eight million people.

She previously starred in teenage drama Grange Hill as well as Jane Eyre, Inspector Morse, Intimate Relations, the Ruth Rendell Mysteries and Belfry Witches.

BBC One controller Lorraine Heggessey said Sadler was a "sweet, modest, hard working girl".

"I'm devastated that we have lost such a talented young actress," she said.

Sadler fell from the Calil flat in Holland Park, London

Sadler suffered severe head injuries in the fall and was taken to Charing Cross Hospital but pronounced dead after her life support machine was switched off.

West London coroner Alison Thompson opened an inquest on Monday and adjourned it pending further inquires.

Police said the balcony from which Sadler fell was very small with a low 26-inch (66-centimetre) perimeter brick wall surround.