London, May 8 (ANI): Cellar girl Elisabeth Fritzl implored a friend to visit her - just before her rapist father Josef imprisoned her in the dungeon.

In a touching letter to an old school friend, which was obtained exclusively by The Sun on May 7, the tragic girl said: "See you soon."

Elisabeth, then 18 and known as Sissy, sent the male friend a series of letters. It has been revealed.

In view of her subsequent shocking ordeal, they are heavy with irony.

In one she told her pal: "I hope you keep your promise that you'll visit me as soon as you get your driving licence."

In another she talked about a night out clubbing, saying excitedly: "We had so much fun."

And in a third, written in August 1984 just 25 days before she vanished, she said: "Basically I'm doing pretty fine."

The sweet-natured letters - in which the full names of her friends have since been Tippexed out, leaving just initials - paint a picture of Elisabeth as a chirpy teenager.

She reveals she had a boyfriend and describes a youthful enjoyment of nights out, a new hairstyle and playing sports, including football.

Some passages suggest she had been ill, was facing a gruelling exam and had spent time in a flat away from her family home.

Elizabeth is now recovering at a clinic in Amstetten with two of the children freed from the dungeon with her 12 days ago - Stefan, 18, and Felix, five.

A third cellar child, 19-year-old Kerstin, is still gravely ill with a kidney infection. (ANI)