The aid worker, Sally Becker, who gained fame in Bosnia as the "Angel of Mostar", was arrested while trying to smuggle a refugee family into Albania according to a British diplomat.

The aid worker was arrested by the Serb authorities near the border with Albania having reportedly crossed into Kosovo illegally.

Serb authorities say Sally Becker is unharmed and being held in the town of Djakovica near the Albanian border.

British diplomat David Slinn said he had been told by unofficial sources that Becker had been sentenced to 30 days' imprisonment.

The Serbian authorities have agreed to allow a British Embassy official to see her, probably on Sunday.

Miss Becker first gained fame as the so-called 'Angel of Mostar', supplying aid to that city during the Bosnian conflict.

'Maverick' reputation

Thousands of ethnic Albanians have fled fighting in the troubled province

She operates independently and the BBC's correspondent in Pristina says she has a reputation as something of a maverick amongst other aid agencies.

As a member of British aid agency Operation Angel she led a team of 26 women volunteers which left Britain last month on a mission to deliver clothing and medecine to Kosovo.