Warsaw: A Polish court on Thursday upheld a decision to extradite an alleged Israeli agent to Germany over claims he was linked to the killing in Dubai of a leader of the Palestinian militant movement Hamas.

"The appellate court has upheld the decision of the court of first instance ruling in favour of the extradition based on a European warrant," a judge at the Warsaw-based appellate court told reporters.

Uri Brodsky, an Israeli citizen wanted by Berlin for allegedly having obtained a German passport under false pretences, is to be handed over to Germany within 10 days, the judge said.

The document was found to have been used by a member of the hit-squad that killed Mahmud al-Mabhuh, the founder of the military wing of Palestinian Islamist movement Hamas, in Dubai in January.

On July 19, Brodsky's lawyers appealed the original July 7 extradition ruling on the grounds that Polish law bars such handovers when the alleged offence is politically motivated.

The hit squad, which Dubai police believe was from Israeli spy agency Mossad, was found to have used 26 doctored foreign passports, sparking diplomatic fallout not only with Germany but also Australia, Britain, France and Ireland.

According to German weekly Der Spiegel, which broke the story last month, Brodsky was arrested on June 4 at Warsaw airport by Polish authorities acting on a European Union warrant issued by Germany.

In the wake of Brodsky's arrest, Israel called on Poland to send him straight home rather than handing him over to Germany.

Polish Prime Minister Donald Tusk dubbed the issue "delicate", pointing to the tragic history between Poland, Germany and Israel.

Nazi-era Germany occupied Poland during World War II. Half of the six million Jews killed by the Nazis in the Holocaust were from Poland.

Warsaw now has close ties with both Germany and Israel, but Tusk said the law leaves Polish justice authorities little room for manoeuvre.