A social worker was today accused of sexually abusing two young sisters while she was working for their family as a live-in nanny.

Elaine Hewitt, now 49, is alleged to have warned one of the girls – who were aged six and ten at the time – she would be taken into care if she revealed what had been going on.

Married Hewitt, from St Helens in Merseyside, was a teenager working as an au pair for a family near Watford, Hertfordshire, when she is alleged to have carried out the abuse more than 30 years ago.

She is now facing nine child sex abuse charges after the younger of the two alleged victims, now aged 38 and 42, went to the police in 2011.

A jury at St Albans Crown Court heard the now 38-year-old had always been ‘uncomfortable’ with Hewitt, who was then called Elaine Duffy, and told police the then nanny had persuaded her to perform a sex act on the defendant on more than one occasion.

Police then contacted the older sister, who claims Hewitt would constantly play the Elton John song Blue Eyes.

‘She cannot listen to the song without it reminding her of what happened,’ prosecutor Sally Mealing-McLeod told the court.

‘The Crown says she abused both girls and that the abuse was of a sexual nature,’ she said.

‘They told no one at the time. It was only a number of years later that they both discussed what had happened and subsequently both reported matters to the police.’

Hewitt was aged 18 when the alleged abuse began in 1981. Hewitt was sacked as the family’s nanny following the girls’ father’s 40th birthday party in May 1982, the court heard.

Hewitt, who was arrested in St Helens in January last year, said she had been the family’s au pair, but denied carrying out any sexual assaults.

She has pleaded not guilty to all nine charges.

One charge of indecency with a child relates to a girl aged between six and seven between May 1981 and July 1982.

The rest relate to a girl aged between 10 and 11 in the period from March 1981 and July 1982.

The trial continues.