Berlin - German officials are drafting legislation to imprison men for up to 10 years if they obtain sexual services from women forced into prostitution, according to the news magazine Der Spiegel on Saturday.

A Justice Ministry spokesman confirmed to Deutsche Presse-Agentur that a discussion document about the bill was under review, but gave no details.

He said the parties in Chancellor Angela Merkel's coalition had agreed to clamp down on prostitution by duress.

Regular prostitution is legal in Germany, with cities zoning land for brothels. Prostitutes appear on TV and pay income tax.

But authorities are concerned that some women, typically illegal immigrants from poor nations in eastern Europe, are employed against their will by pimps who demand repayment of vast "recruitment fees."

The new rules would make it a crime for a man to commit sexual abuse "in a situation where the victim is helpless." Currently it is not a crime to buy the services of a prostitute in Germany.

Spiegel said lawyers in Merkel's own Christian Democratic Union (CDU) considered the draft too weak because a customer could avoid prosecution by saying he did not know.

Legislator Siegfried Kauder said the sexual act should also be a crime if a customer carelessly ignored evidence of duress, such as bruises on a woman.

The justice spokesman said there were plans to pass the legislation before the autumn 2009 general election. (dpa)