A Polish newspaper wants Germany's Australian Open winner Angelique Kerber to return to her roots and play for Poland, but the Grand Slam winner insists "I'm German".

Warsaw-based daily Gazeta Wyborcza wants to see Bremen-born Kerber, who will play for Germany in this weekend's Fed Cup clash against Switzerland in Leipzig, turn out for the nation of her ancestors.

"Very often, the media portray Angelique as a German of Polish origin, and that is not true. She has a Polish passport, pays taxes in Poland and her parents are Polish," wrote the newspaper.

But Kerber, who moved to Poland in 2012 to be near her grandparents, put the matter to bed by telling Stern TV she is German through and through.

"It's true that I now live in Poland and have a relationship with the country, because my parents live there and I have also trained there," said the world number two.

"But I am German, I play for Germany, I grew up in Germany and my heart beats for Germany."

Her parents Beate and Slawek raised Kerber in Kiel, while her grandparents Maria and Janusz live in the small town of Puszczykowo, near Posen, and had a big influence on her career.

Her grandfather owns the town's tennis centre and Kerber has spent time training there.

"My grandfather has a big influence on me, without him I wouldn't be where I am now," she said.

"He has always believed in me and without both of them, I wouldn't have won in Australia.

"Puszczykowo is an important place in my life, I feel like I am at home there," Kerber added, having flown to see her grandparents straight after winning in Melbourne.

Kerber says her aim now is to knock Serena Williams, who she beat in last Saturday's Australian Open final, from top spot in the WTA world rankings.

The American star has been number one for 278 weeks and only legends Steffi Graf (377 weeks) and Martina Navratilova (322) have been on top of the rankings longer.

Despite having an impressive 5,700 tour points to her credit, Kerber has a long way to go to catch Williams' enormous tally of 9,245.

Meanwhile, Swiss star Martina Hingis has said Kerber can capture more major titles after her breakthrough victory in Australia saw her become the first German Grand Slam champion since Graf at the 1999 French Open.

"She has the potential, she proved that in Melbourne," said Hingis, the world's top ranked doubles player, ahead of Switzerland's World Group first-round clash against Germany.

With her Swiss team-mates Belinda Bencic and Timea Bacsinszky both ranked in the world's top 15, Hingis, 35, is unlikely to be used in the singles rubbers.

The Germans, who lost to Russia in last year's semi-finals, have their work cut out to progress with Kerber their only top-20 ranked player.

"I can give some input from the bench, positive energy doesn't do any harm," said Hingis, who has won five Grand Slam singles titles in her career.

Hingis won her 12th Grand Slam doubles title in this year's Australian Open final with her Indian partner Sania Mirza.