Gillian Gibbons is described as "a talented and able teacher "

Colleagues of Gillian Gibbons, 54, from Liverpool, said she made an "innocent mistake" by letting the six and seven-year-olds choose the name.

Ms Gibbons was arrested after several parents made complaints.

The BBC has learned the charge could lead to six months in jail, 40 lashes or a fine.

Officials from the British embassy in Khartoum are expected to visit Ms Gibbons in custody.

"We are in contact with the authorities here and they have visited the teacher and she is in a good condition," an embassy spokesman said.

The spokesman said the naming of the teddy happened months ago and was chosen by the children because it is a common name in the country.

"This happened in September and the parents did not have a problem with it," he said.

'Very sensitive'

The school has been closed until January for fear of reprisals.

Fellow teachers at Khartoum's Unity High School told Reuters news agency they feared for Ms Gibbons' safety after receiving reports that men had started gathering outside the police station where she was being held.

The school's director, Robert Boulos, said: "This is a very sensitive issue. We are very worried about her safety.

They came up with eight names including Abdullah, Hassan and Muhammad

Robert Boulos

Director of Unity High School

"This was a completely innocent mistake. Miss Gibbons would have never wanted to insult Islam."

Mr Boulos said Ms Gibbons was following a British national curriculum course designed to teach young pupils about animals and this year's topic was the bear.

Ms Gibbons, who joined the school in August, asked a seven-year-old girl to bring in her teddy bear and asked the class to pick names for it, he said.

"They came up with eight names including Abdullah, Hassan and Muhammad," Mr Boulos said, adding that she then had the children vote on a name.

Twenty out of the 23 children chose Muhammad as their favourite name.

Mr Boulos said each child was then allowed to take the bear home at weekends and told to write a diary about what they did with it.

He said the children's entries were collected in a book with a picture of the bear on the cover and a message which read, "My name is Muhammad."

Book seized

The bear itself was not marked or labelled with the name in any way, he added.

It is seen as an insult to Islam to attempt to make an image of the Prophet Muhammad.

Mr Boulos said Ms Gibbons was arrested on Sunday at her home inside the school premises after a number of parents complained to Sudan's Ministry of Education.

I know Gillian and she would never have meant it as an insult. I was just impressed that she got them to vote

Muslim colleague in Sudan

He said police had seized the book and asked to interview the girl who owned the bear.

The country's state-controlled Sudanese Media Centre reported that charges were being prepared "under article 125 of the criminal law" which covers insults against faith and religion.

No-one at the ministries of education or justice was available for comment.

Mr Boulos told the BBC he was confident she would not face a jail sentence.

One Muslim teacher at the independent school for Christian and Muslim children, who has a child in Ms Gibbons' class, said she had not found the project offensive.

"I know Gillian and she would never have meant it as an insult. I was just impressed that she got them to vote," the teacher said.

In Liverpool, a family spokeswoman said Ms Gibbons' grown children, John and Jessica - both believed to be in their 20s - were not commenting on her arrest.

Gillian Gibbons had been working in Khartoum since August

"I have spoken with her children and they do not want to say anything and aggravate the situation over there," she said.

Rick Widdowson the headteacher of Garston Church of England Primary School, where Gillian worked for ten years, added: "We are an Anglican school and I know for a fact that Gillian would not do anything to offend followers of any faith.

"Certainly she is also very worldly wise and she is obviously aware of the sensitivities around Islam."

Cartoons depicting the Prophet Muhammad printed in several European newspapers sparked violent protests around the world in 2006.