The sister of a Bradford journalist facing a possible life sentence in a Bangladeshi jail said today she believed the arrest had been a "terrible misunderstanding".

Concern is growing for television reporter Zaiba Naz Malik, 33, who is being held on suspicion of anti-state activities by police in Dhaka, the Bangladesh capital.

Today her sister Adeeba told how the family in Bradford had been unable to contact Zaiba since she was arrested, along with two other members of her Channel Four film crew, on Monday.

Adeeba, who also has two brothers, said she was struggling to explain to her mother what had happened.

Zaiba, a talented journalist who had been recording a film about political life in Bangladesh, had been due to pick up a women's film and television award for newcomer of the year in London next week.

"We are just hoping that she will be back in time for that," Adeeba said today, "We are just concerned for her at the moment. We very much hope for Zaiba's sake that the situation will be resolved as quickly as possible."

Adeeba, who is deputy chief executive of Bradford-based Quest for Economic Development, said the family was hoping to fly out to Bangladesh but were having difficulty obtaining visas. "It is difficult because we are not able to communicate with her in any way. But my understanding is that she is well, considering the situation she is in, and we are reassured by the fact that a lot of activity is taking place to resolve this."

Zaiba had completed filming for a Channel Four-commissioned documentary Unreported World when she was arrested while attempting to cross the border into India.

Police seized a video camera and cassettes on Monday and Zaiba appeared in court with the crew on Tuesday. She was remanded in custody for five days to allow further questioning.

Although the group have still not been formally charged, police officials have said they have "enough evidence" to prove the allegations, which could carry a life sentence.