(CNN) -- The United Arab Emirates on Saturday expressed concern about a German court's decision to release an alleged Israeli agent being investigated in connection with a Hamas leader's murder in Dubai.
The suspected agent, who often uses the alias Uri Brodsky, is under investigation for helping obtain a false German passport allegedly used by one of the killers in January.
The UAE's foreign ministry said it's worried about Brodsky's release on bail and his freedom to return to Israel during the probe, the state-run WAM reported.
Brodsky still faces a possible trial in Germany
"The UAE seeks assurances that Brodsky is in no way connected with the murder of Mahmoud al-Mabhouh in Dubai in January of this year," ministry official Abdurahim Al Awadhi said in a statement.
"As this may relate to a serious crime committed in Dubai, the UAE expects full and close cooperation from the German authorities and will continue to pursue the matter through diplomatic channels," the statement said.
Dubai is one of seven emirates within the United Arab Emirates.
Rainer Wolf, a spokesman for the state prosecutor's office in Cologne, Germany, told CNN that the judge decided that keeping Brodsky in custody was excessive considering the severity of the charges and released him on bail.
Brodsky was arrested in Poland two months ago on a European warrant as part of an investigation into the killing.
That warrant accused him on two counts: espionage and forgery. Poland granted Germany's request for extradition but on the condition that it would only be for the forgery charge.
Mahmoud al-Mabhouh, a founding member of the Palestinian group Hamas' military wing, was found dead in January in his hotel room in Dubai in the United Arab Emirates. Police believe he was killed the night before and suspect the Mossad, Israel's foreign intelligence unit, was behind the assassination.
Several countries including Ireland, the United Kingdom and Australia have kicked out Israeli diplomats after concluding Israel had probably forged their countries' passports as part of the operation.
Dubai police have identified 33 suspects in al-Mabhouh's killing. Most of the suspects are believed to have acquired faulty passports to go to Dubai and then fled to other far-flung locations, police said.
Israel has maintained there is no proof linking it to the doctored passports or the killing of al-Mabhouh.
Israeli Foreign Minister Avigdor Lieberman told Israel Army Radio in March that there is certainly no reason to think that the Mossad and not some other intelligence agency of another country operated there.