Polish authorities have reportedly arrested a suspected Israeli agent in connection with the murder of a Hamas operative in Dubai in January.
German prosecutors say the agent was arrested in early June. Media reports named him as Uri Brodsky.
Germany is seeking his extradition over a forged German passport used by one of the killers, the prosecutors say.
Mahmoud al-Mabhouh, one of the founders of Hamas’s military wing, was found dead in a Dubai hotel on 20 January.
Dubai police have said they are 99% sure Israeli agents were involved, but Israel says there is no proof.
On Saturday, German prosecutors said the agent had been arrested on a warrant issued by Germany, as he arrived in Poland.
“It’s now up to the Poles to decide if they are going to hand him over,” a spokesman for the federal German prosecutor’s office told AP news agency.
There have been no comments so far from the Polish or Israeli authorities.
Forged passports from Britain, the Irish Republic, France, Australia, and Germany were used in the Dubai operation, leading to diplomatic rows between those countries and Israel.
The UK and Australia have expelled Israeli nationals over the forgeries.