Amir Ben-Asher and Yaacov Bak, both former army officers, are accused of being hired by a former Israeli policeman now living in Russia to arrange for the killing of three Russian businessmen who now live in Israel. A bonus was promised after the first murder was carried out.
In recent years Israel has been an important transit point for the Russian mafia, according to police.
Not only are there some 600,000 Russian Jews in the country but Israeli currency laws are lax enough to allow immigrants to bring in money safely.
Starting in the summer of 1993, the mafia has held a series of meetings here, the first at the Tel Aviv Hilton.
The so-called Organizatsiya grew up in the 1970s and 1980s in the Soviet Union.
Many gangsters later emigrated to New York, claiming to be Jews, although this was true of only one third, police say.
With about 300 members outside Russia, their extreme violence enabled them to gain control of part of the drug trade and other rackets, as well as making vast profits in Russia after the break-up of the Soviet Union.
At first meetings were held in Cyprus but this was considered unsafe and half a dozen senior mafia members came to live in Israel.
Last year a ton of cocaine was intercepted as it left St Petersburg for Israel, probably on its way to Western Europe.
Until the case of Mr Ben-Asher and Mr Bak, however, the Russian mafia was careful not to carry out crimes in Israel itself. According to the police, the two private detectives gave the criminal they hired to carry out the killing - he later turned state's evidence - a pistol with a silencer as well as photographs of the intended victims whom they were watching.
A search by the police of the detectives' apartments in Tel Aviv revealed seven pistols, one with a silencer, and two grenades.
Neither man is co-operating with the police but both were arrested last year in connection with a wire-tapping scandal involving Ma'ariv newspaper.