Prominent Bahraini human rights defender Maryam Al-Khawaja has been sentenced to one year in jail for assaulting a policewoman, according to her lawyer.

The verdict was announced in the absence of al-Khawaja, who announced with an article on the Index on Censorship website that she would not attend the hearing because "it is not possible to have a fair and independent trial in Bahraini courts as they stand".

Al-Khawaja was detained early in September after her arrival at Bahrain's Manama airport where she travelled to visit her jailed father, pro-democracy activist Abdulhadi al-Khawaja. She was released dependent on a guarantee of her place of residence and travel ban.

She has been in London since a travel ban was lifted on 1 October.

Al-Khawaja holds dual Bahraini and Danish citizenship, and is co-director of the Gulf Centre for Human Rights (GCHR) which has offices in Copenhagen and Beirut.

In her article, the activist condemned the "highly flawed" Baharini judicial system and denounced the human rights violations she was subjected to since she arrived in Bahrain. "There are medical reports about the injuries I sustained during the assault I was subjected to, for which I continue to need physiotherapy," she said.

The presiding judge of the case, Mohammed Ali al-Khalifa, brought other cases against al-Khawaja family and other pro-democracy activists.

Maryam al-Khawaja also said she was refused access to her lawyer during interrogation in Bahrain. "The way that the public prosecution deals with politically motivated cases is it uses all aspects of the government to provide impunity for the perpetrators of violations," she wrote.

"I find any and all cooperation with the court or attendance of the hearings by myself as a problematic legitimisation of an unfair and biased court," she continued. "Therefore I have decided to boycott the hearings, and have asked my lawyer to do the same."

Another Bahraini activist, Nabeel Rajab, who was recently freed after spending two years in prison for taking part in "illegal gatherings" in the Gulf country, told IBTimes UK in September that assaulting police "is a common charge in Bahrain when they have nothing against you."

"They simply wanted to take her by force and she refused," he said.

Al-Khawaja was previously prevented from boarding a British flight to Bahrain because of a ban issued by the government of the Gulf kingdom.

Her father Abdulhadi, 54, is jailed for life for plotting to overthrow the kingdom. He staged a 110-day hunger strike in 2012 over his imprisonment, and sent a letter to the prison authorities saying that "he would go on a hunger strike until he is released".

Amnesty International and Human Rights Watch describe Abdulhadi as a "prisoner of conscience."