As Michelle Hogg, 33, prepares herself for a life forever looking over her shoulder, she may reflect this morning with mixed blessings on her chosen occupation.

The skills as a make-up artist that first drew her to the attention of the Securitas robbers could save her life as she prepares to adopt a new identity under the witness protection scheme. No one in the criminal underworld will know her name or address. To them she will simply be a “grass”.

The prosecution’s star witness, who created prosthetic masks for the robbers, admitted to the Old Bailey that she was petrified after identifying members of the gang.

Her last-minute decision to name them proved pivotal in securing the convictions of her former co-defendants. In exchange, the Crown Prosecution Service agreed to drop the charges against her. But her initial willingness to cooperate with the gang may reduce public sympathy for her.

Ms Hogg, who studied theatrical make-up at the London College of Fashion and had worked on cosmetics counters in Harvey Nichols and Selfridges, became involved in the Securitas plot after one of the gang, Lea Rusha, became convinced that her skills would mean they could never be traced.

Her naming of him along with Stu-art Royle, Jetmir Bucpapa, and Roger Coutts, as well as three other people whose names cannot be published for legal reasons, left them entirely exposed.

For the mask moulds Ms Hogg used a variety of materials including latex, Vaseline, cotton pads and sponge. She then dressed them with modelling wax, dental plaster, make-up, grease-paint, false hair, hair dye and face powder. She used her bra straps to pin back one man’s eyes to give them a more slanted look and inserted the rubber teats of a baby bottle into his nostrils.

When police found her less than 24 hours after the robbery after a tip-off, they found a bin containing £400 worth of such products as well as wrapping paper from two theatrical suppliers in London. As officers led her away in tears from her flat in Plumstead, southeast London, she said that she would not comment, claiming that if she did, she and her family would be in danger.

In a statement handed to detectives later, Ms Hogg wrote: “I would like to assist the police further so I could establish my innocence but I am terrified as to what may happen to me and my family if I say too much. I do not think the police could protect me or my family from harm.”

Her plight has been compared to that of Danielle Cable, now 27, who feared for her life after becoming a key prosecution witness by identifying Kenneth Noye as the killer of her fiancé, Stephen Cameron. Noye had served eight years for his part in the Brinks-Mat gold bullion robbery.

During legal arguments before the Securitas case started last summer, Ms Hogg’s barrister said that she had been put on medication because of acute bouts of depression and a nervous breakdown triggered by the charges of robbery and kidnap. The decision to drop the charges was taken after discussions between Sir Ken Macdonald, the Director of Public Prosecutions, and the police.

Roger Coe-Salazar, the Chief Crown Prosecutor for Kent, said: “We did not accept that Michelle Hogg had no knowledge of what she was doing and we still don’t.” The decision to drop charges against her was “public-interest based”, he added.

Detectives remain sceptical of Ms Hogg’s defence that she believed the gang needed the disguises because they were planning an amateur dramatics show or were going to appear in a pop video. She told the court: “They wanted to give me money. I didn’t want any money.”

As her new life begins this morning she may recall writing on her CV that she was “perceptive to new techniques and ideas”.

She probably did not realise how her career in “theatrical and corrective make-up” could demand that she adapt to a totally new life, forever fearing reprisal.

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