Benjamin Netanyahu has publicly condemned the jail sentence given to a US-Israeli woman in Russia after she was caught with a small amount of marijuana.
Naama Issachar, 26, was sentenced on Friday to seven and a half years for smuggling, after she was caught with nine grams of the drug in her luggage when she arrived in Russia for a connecting flight to India in April.
The amount she was carrying was legal for personal use in Israel. The New York Times reported possession of such an amount would normally mean no more than a month's detention in Russia.
On Friday, Mr Netanyahu's office issued a statement that said he been involved in the case for some weeks, raising it with Russian President Vladimir Putin when the pair met in Sochi on September 12.
The Israeli PM's office said: "The punishment being demanded by the Russian prosecutor is disproportionate and does not fit the nature of the offence being attributed to Issachar."
Russia has tried to exchange Ms Issachar for Aleksey Burkov, a Russian hacker whom Israel is due to extradite to the United States on embezzelment charges.
Her family believe her harsh sentence is intended to pressure Israel into releasing Burkov.
Israel's Kan public broadcaster reported that her detention privileges - including phone calls, family visits and access to kosher meals - were severely restricted after Burkov's extradition was approved.
