Jailed activist Abdulhadi Al-Khawaja was feared to have died, his lawyer said on Monday, after Bahraini authorities turned down repeated requests to contact him.

"Authorities have been refusing since yesterday [Sunday] all requests, made by myself and by his family, to visit or contact Al-Khawaja," Mohammed al-Jeshi told AFP.

"We fear that he might have passed away as there is no excuse for them to prevent us from visiting or contacting him," he said, adding that no information was available on Khawaja's health.

Jeshi said the last time he contacted Khawaja was on Saturday, a day after he was moved from the interior ministry hospital into a military hospital in Manama.

Khawaja, a Shiite who was condemned with other opposition activists to life in jail over an alleged plot to topple the Sunni monarchy during a month-long protest a year ago, began a hunger strike on the night of 8-9 February.

Denmark has asked Bahrain to send Khawaja, who is also a Danish citizen, to the Scandinavian country. Bahrain's official news agency BNA reported Sunday that Manama had turned down the request.

But Danish papers quoted the head of the foreign ministry's consular service, Ole Engberg Mikkelsen, as saying that "a [formal] reply will come through diplomatic channels and not via a news agency or Twitter."

Mikkelsen said he did not know when Manama would send its official reply.

"Unfortunately there is not much time. It is a case where the clock is ticking," he said. "We are continuing our efforts to convince Bahrain that it is in everyone's interest that he be extradited."

Front Line Defenders, a Dublin-based NGO, warned that Khawaja could now die in jail, while Bahrain's largest opposition movement, Al-Wefaq, said refusing to allow a transfer to Denmark amounted to having "signed his death" sentence.