Gerson Liebl, 46, was detained by police last week pending possible deportation to Togo, the West African state where he was born. His wife and son were arrested a few days later. The entire family is now being held in a detention center in Berlin's eastern outskirts.

Reached by phone Sunday, Dec. 15, Liebl told German news agency DPA that he and his wife were on hunger strike in protest at the police action.

"It's illegal what they have done," he says. "I've done nothing wrong.

"I'll fight the authorities all the way if their intention is to kick me and my family out of the country," he says, adding that his son had been due to start school in Berlin on Monday.

Liebl says the possibility that he and his family would be sent back to Togo after 17 years was personally shocking.

"I'm of German descent," he insists. "I'm battling for the abolishment of racist colonial laws which are still valid today in Togo."

Colonial origins

Liebl says his claim to German citizenship dates back to the late 19th and early 20th centuries when Togo was a German protectorate.

He says his late grandfather, German-born Friedrich Karl Georg Liebl, was a specialist in tropical diseases at a hospital in the Togolese capital Lome. Liebl says that while his grandfather was based in Lome he had fallen in love with Kokoe Edith Ajavon, the daughter of a local chieftain.

He says the couple had a son, Johann Baptist Liebl, and were wedded in a traditional African-style tribal ceremony in Togo. Mixed marriages were banned under German imperial law and Johann was registered as a mixed-race child.

In 1911, Karl Liebl returned home to Straubing, Bavaria, leaving his African bride and son behind in Togo. In 1962, Gerson Liebl -- the son of Johann Baptist -- was born.

Seeking asylum

Bright at school, Gerson says he learned German and got a job as a goldsmith before flying to Frankfurt in 1991 to seek asylum and later German citizenship. This was when his long struggle with the German bureaucracy began in earnest, he says.

Officials argued that Gerson's father, Johann Baptist, had never possessed German citizenship, nor did he qualify for it under colonial law. Ordered to leave the country, Gerson Liebl refused to comply.

Police raided his apartment and during a scuffle Liebl claimed he suffered injuries. Later he was given a nine-month suspended sentence for resisting arrest. But it emerged that police had acted without an arrest warrant and the sentence against him was quashed.

Eventually, Liebl and his family were allowed to remain in Germany, and he moved to Straubing, where his grandfather had once lived.

Case heard in Germany's highest court

But in 2005 Liebl's residence permit expired and was not extended due to a technicality. He was also out of work. He then raised his grievances with a German parliamentary committee set up to deal with foreigners' grievances.

In Straubing, town hall officials speak of Liebl's extraordinary tenacity in his legal battles and the rows of files relating to his case that line office bookshelves.

Martin Panten, the head of Straubing's foreigners' affairs office, says that in the 13 years he's been working there he has never known a case like Liebl's. "He contests everything," says Panten.

On three occasions Liebl has taken his case to Germany's highest court, the Federal Constitutional Court. "That's most unusual," Panten told German newspaper Berliner Zeitung.

While there is a degree of sympathy for Liebl's difficulties, Straubing officials say there is nothing they can do to help him. "We cannot change the nation's laws. Only the Bundestag (the German parliament) can do that," Panten says.

But in March this year, Bavaria's highest administrative court rejected Liebl's latest bid to remain in the country and receive German citizenship.

His 17-year tussle with German officialdom appearing to have come to a sad end, Liebl says he has no other choice but to embark on his hunger strike in the hope it will push government authorities to re-evaluate his claim to live in Germany.