By Ray Furlong BBC correspondent in Berlin

Media in Germany have reported that Michaela Spitzer, 45, died of exhaustion in the desert, although the authorities in Germany and Algeria declined to either confirm or deny the report.

The tourists are believed to have been abducted by Islamic militants.

In the interest of the hostages who are still in a very difficult situation, the government cannot give any information. German spokesman

The death of the German woman was reported by several news media outlets here.

National television said her body had been found buried in the desert, while a leading newspaper quotes her ex-husband as saying that German police informed him of her death.

It is thought she died in the 50 C heat of the Sahara desert, where she disappeared in March.

The German authorities have refused to comment, beyond saying that they did not want to endanger the lives of the hostages.

Families' anguish

Of 32 tourists originally kidnapped, 17 were freed in a raid by the Algerian army in May.

It is thought the remainder are being held by Islamist rebels.

In recent days, there has been speculation in the media both here and in Africa that the kidnappers have taken their remaining captives over the border into Mali.

As late as Monday, the Algerian interior minister said efforts were still under way to free them.