A landmark trial in Egypt has seen the doctor and father of a 13-year-old girl who died after allegedly undergoing female genital mutilation (FGM) walk free.

Both men were cleared of all charges, after insisting that teenager Suhair al-Bata'a, who died in June last year, was killed by a penicillin allergy.

Campaigners have expressed their disappointment with the outcome of the trial, with hopes for a crackdown against FGM now dashed. Manal Fawzy of the Childhood and Development Association told the BBC that "Now it will be easy for any doctor to perform such surgeries."

"Of course there will be no stopping any doctor after this. Any doctor can do any FGM he wants now," Atef Aboelenein, a lawyer for the Women's Centre for Guidance and Legal Awareness, has also warned.

FGM is illegal under Egyptian law, but the practice remains alarmingly widespread. Suhair's case was the first time that a doctor has been brought to trial in the country on charges of undertaking the procedure.

Dr Raslan Fadl denied carrying out FGM. He said he removed a wart from Suhair's genital area, making only a small incision.

However, evidence provided by Egypt's forensic authority "proved what happened in the genital area of the girl was a clear circumcision operation," the prosecuting lawyer said.

The judge did not give a reason for his not-guilty verdict yesterday. It was not even announced in the courtroom, but was instead written on a leger.

"It is awful that after what seemed to be strong moves towards a positive outcome, Suhair has not been given justice," said Suad Abu Dayyeh from Equality Now, an NGO which has campaigned on the case.

"It sends a very negative message. It was the first case in the country and we were hoping we could build on it."

She urged the Egyptian government to "take FGM seriously," adding that it is "vital" to protect millions of women and girls who are at risk.

FGM is also known as female circumcision, or female genital cutting, and refers to any procedure that removes part or all of the external female genitalia, or alters or injures the genital organs in any way without medical reason.

Unicef estimates that more than 90 per cent of Egyptian women under 50 have undergone the procedure. It is regarded as a rite of passage into womanhood by many cultures, while some believe that it makes a woman less likely to commit adultery.

A summit was held in London in July of this year in the hopes of mobilising initiatives to end FGM and forced-marriages around the world.

125 million girls worldwide are thought to have undergone the procedure, and David Cameron has set up a £1.4 million FGM prevention programme. He has denounced the practice as "abhorrent".

"All girls have the right to live free from violence and coercion, without being forced into marriage or the lifelong physical and psychological effects of female genital mutilation," he said.

"Abhorrent practices like these, no matter how deeply rooted in societies, violate the rights of girls and women across the world, including here in the UK."