Elisa Sales, 19, of Kingsway, was sentenced to two years in prison after pleading guilty to burglary at Warwick Crown Court.

Prosecutor Tammy Mears said Sales used her old key to steal money from The Health Spa, in Warwick Street, on 120 occasions up to February 22 this year.

When the owner noticed takings were down she contacted the company that operated the firm's alarm, which found the alarm was regularly being deactivated for just five minutes between five and six in the morning.

As a result all the staff fell under suspicion and in February the owner secretly installed a CCTV camera.

Footage showed someone stealing money during the night, but the image was too grainy to identify the culprit.

A secure box was installed for takings, but the thefts continued and the offender was shown standing on a chair and using a fork to hook cash out of the box.

Sales was finally arrested at the end of February, when the police caught her leaving The Health Spa at 6.30am with £110 cash.

Miss Mears said Sales accepted taking a total of £17,000 to £20,000, but the owner thinks the actual amount stolen is between £31,000 and £50,000.

Nick Devine, defending, said Sales, who was on a low wage, started to take small amounts of money while she still worked at the salon so she could "stand her round" when she went out.

He added: "There is genuine remorse and regret."

Sentencing Sales, Judge Marten Coates said: "The system you used was sophisticated. Your dishonesty was persistent, it was against your employer and every person you worked with came under suspicion."