A woman who taught missing Margaret Fleming told a murder trial she had a reading age of eight and struggled with writing.

Jacqueline Cahill, 56, who taught Ms Fleming standard grade English at Port Glasgow High between 1994 and 1996, was giving evidence at the High Court in Glasgow.

Edward Cairney, 77, and Avril Jones, 59, deny murdering her at Seacroft, Main Road, Inverkip, between December 18, 1999 and January 5, 2000.

Ms Fleming, who would now be 38, has allegedly not been seen for more than 19 years.

A huge police investigation to find Ms Fleming was launched in November 2016 which involved a poster campaign and searches with police dogs and divers.

Cairney and Jones claim she left Inverkip in January 2000 with a members of the travelling community but returned from time to time over the years to collect her benefit money.

Mrs Cahill, who now works for North Lanarkshire Council, said in 2016, as part of the investigation, police showed her letters allegedly written by Ms Fleming to Cairney and Jones.

One letter was headed from Carlisle on January 9, 2000, and the other two from the Regent Palace Hotel in London on January 13, 2000.

Mrs Cahill said: "It is not letters Margaret would be capable of writing.

"She had literacy difficulties.

"She struggled to put pen to paper.

"She struggled to read and read around about the level of an eight-year-old."

She told the High Court in Glasgow that Ms Fleming needed a support teacher to help with her writing and added: "Margaret's level would be 100 words.

"A number of difficult words in the letters are correctly spelt and there is a stream of consciousness in the writing. Margaret could have written 100 words with short sentences and one idea.

"I would be doubtful about Margaret using a phrase like 'stopped in your tracks.' Her literacy skills were not great. She would write in short sentences and she wasn't particularly imaginative."

The jury was shown the three letters which were all typed. The first from Carlisle was signed 'Mags' followed by six kisses and six hugs. In the other two the name Margaret was typed.

Defence QC Thomas Ross, who represents Cairney, asked Mrs Cahill, who last taught Margaret in 1996,: "How did you get a look at Margaret's previous work to compare it to the letters," and she replied: "I didn't have to I could remember Margaret's school work."

Mr Ross then said: "From memory you were comparing the ability of a child you had not seen for 21 years," and Mrs Cahill said: "That's true."

She added: "I do remember Margaret's work and I have every confidence saying this."

Mrs Cahil was asked if Ms Fleming's ability at reading and writing would have improved after she left school and she said: "I would find that extremely unlikely."

Cairney and Jones are also accused of defrauding £182,000 in benefits and attempting to defeat the ends of justice by claiming Ms Fleming was alive.

They deny all the charges against them.

The trial before judge Lord Matthews continues.