Mysterious letters, lights being turned on, school bells ringing for no reason and even the flooding of a room are things which have been blamed on an angry and bitter ghost which is haunting the halls at Trinity High School in Woodford Green. Charlie Stong set out on a trail to find the spirit.

AT times Dr Paul Doherty describes the ghost at Trinity High School as if it were a bodily ailment.

"It's a mild irritation," he says as if it were a wisdom tooth peeking through.

"I will not be driven out, and I will beat it," he adds, determined not to be defeated by some sort of cancerous growth.

And it is not surprising that this irritation' gets on the headteacher's nerves so much.

For it has disrupted him when visiting the school at weekends to catch up on important paperwork, has scared the wits out of a pet Jack Russell dog, has frightened his secretaries and caretakers, and once even interrupted his Christmas dinner.

Trinity Catholic High School, in Mornington Road, Woodford Green, was built in 1884 by Henrietta Pelham-Clinton, the then Duchess of Newcastle. Its original use was as an education establishment for young girls who worked in the sweat shops' of Mile End Road.

It then became a convent, until 1976 when it became Trinity.

Dr Doherty believes the ghost of the school is a bitter and resentful nun who lived here a long time ago and regards the place as her own.

His theory is backed up by a succession of letters the school received.

Dr Doherty explained: "In the mid 1980s we used to get letters addressed to a nun, called Imelda I think. I started opening these letters but there was never an address on the top so we do not know who they came from.

"The letters always said things like leave me alone, stay out of my dreams'."

The ghost has never been seen or heard by a student, but Dr Doherty says it can only been seen or heard when there are very few people in the building.

He continued: "The only time I backed off was one Saturday. I'd come in to catch up and had been drinking tea all afternoon so I made my way to the gents' toilets down the corridor. I just froze because I could hear this whispering at the top of the stairwell. I called the secretary and she also could hear it. I thought I'm going to be really macho'. So I put the light on and said who's there?'. But as I did the bulb went and I thought I'm not going up there'."

On another occasion, the last person to leave the building, Dr Doherty was outside and saw an old woman's face pressed tight against a window on the second floor, the floor where the ghost is always seen and heard.

Dr Doherty added: "A couple of times I've turned off the lights at the top of the stairs and there seems to be someone standing at the bottom by the stair post."

No records are left of the building before 1976, as the nuns took all evidence with them on their departure, and there are several things which cynics would highlight, such as the fact that it is a very old building and as Dr Doherty puts it "God knows what the water system is like".

What also has to be taken into account is the fact that Dr Doherty is a writer and likes to elaborate, but you get the feeling that there really is no reason for him to be making all this up.

He said: "On Christmas Day 1981 I was at home and I got a phone call from Woodford police station.

"They said they had had complaints that all the (school) lights were on and all the bells were ringing. I said For God's sake it's Christmas Day and I'm eating my dinner. Where's the caretaker?' They said they had already called him but he was very merry.

"So myself and two male guests went to the school and every light was on and the bells were ringing. We never found any evidence of a break-in. That was really scary."

Dr Doherty was not taken by my suggestion of a possible exorcism, emphasising again the irritation' factor of the ghost rather than any aggressive tendencies.

He said: "After a while it becomes irritating and you just think will you shut up?' One day the handle of my office door was moving when I was inside and I knew I was the only person in the building.

"I got so fed up with it that I thought I'll open the bloody door and if you want to come and join me you can'."

The biggest problem the ghost may have caused is a flood in 2004. New radiators had been fitted in the school.

On a Saturday night Dr Doherty, his wife and a few friends enjoyed a cheese and wine evening. On their departure Dr Doherty locked the door. He returned the next day to find a radiator pipe not only broken but forcibly pulled away from the wall. The room was flooded. But there was no broken window, nor any evidence of tampering with the door to Dr Doherty's office.

Only one possibility remained; was this yet another irritation' caused by Imelda?

9:00am Tuesday 13th December 2005