A Bradford journalist held on suspicion of anti-state activities in Bangladesh has been told she cannot see her lawyers, despite a court ruling that she should be able to meet them.

The legal team working for Zaiba Naz Malik had been told access would be granted to the TV reporter and two colleagues who are being held in the Bangladeshi capital Dhaka.

But when they arrived for their scheduled appointment the lawyers were told they could not see the journalists, and fresh food and clothing was also refused.

Today Channel Four said it was "extremely concerned" at the developments and said it took a "very serious view" of the denial of "basic human rights".

A spokesman said lawyer Ajmalul Hossain QC was refused entry despite carrying a court order stating access must be given. Legal firm Hossain and Associates has also not been handed certified copies of the allegations against Miss Malik and cameraman Bruno Sorrentino.

The spokesman said: "Channel Four is extremely concerned that two of its journalists and their interpreter are being denied their constitutional right to consult and be defended by a lawyer.

"Since their arrest no access has been granted to either consulate officials or lawyers.

"Lawyers instructed by Channel Four have followed the legal process in Bangladesh but Zaiba and Bruno have been denied their fundamental constitutional right in accordance with basic human rights principles to meet with their legal representatives. Channel Four takes a very serious view of these developments."

Tim Gardam, director of television at Channel Four, has now sent a letter to the Bangladesh authorities explaining that the crew had been granted permission to film the programme on political life there.

The BBC's head of current affairs, Peter Horrocks, has also written to the High Commissioner of Bangladesh appealing for their safe release.

Mr Horrocks was aware of Miss Malik's work following her time on the Panorama and Corresp-ondent programmes.

"These journalists are well known to the BBC," he wrote. "We know them to be journalists of high integrity, who would only conduct their journalism in a professional and objective manner."

Stephen Jakobi, director of the campaign organisation Fair Trials Abroad, said he was not aware of any other journalists being held in Bangladesh on such allegations in recent years.

But he warned it could be difficult to secure a fair trial if charges are brought against the crew.