BERLIN, Jan 29 (Reuters) - Deutsche Bank's chief executive on Monday warned about the threat of right-wing extremism in the lender's home market, saying the rise of the nationalist Alternative for Germany (AfD) risks investment in Europe's largest economy.

The comments at a bank reception in Berlin are the most extensive yet on the subject from the CEO of Germany's top bank. They are also the latest in a series of similar warnings from German companies and their CEOs following an investigative report about a meeting, where plans for mass deportations of citizens of foreign origin were discussed with some AfD members.

Elections this year in several German states will be critical "to the future of our democracy - and our business location", Deutsche Bank's Christian Sewing said.

International investors are becoming "increasingly sceptical" and "questioning whether they can trust the democratic values and structures that are an important factor in their investment in Germany in the long term", he added.

Germany's business leaders typically stay out of party politics given swings in power and have long stayed silent about the rise the AfD, which is now polling second in nationwide polls.

Hundreds of thousands of Germans have also demonstrated against right-wing extremism in recent weeks following the report of the meeting, which discussed proposals for "unassimilated citizens" to be deported to "a model state in north Africa"

The AfD has sought to distance itself from the deportation proposal aired at the meeting with right-wing radicals, saying it is not party policy. (Reporting by Christian Kraemer and Tom Sims; Editing by Sharon Singleton)