An article highlighting the case of one of the three American hikers detained in Iran mentions Kian’s case as well:

“…A U.S. official, speaking on condition of anonymity because of the diplomatic sensitivity of the matter, said the government is doggedly working behind the scenes with the Swiss government to secure the three hikers’ release. The official said the issue was raised on Oct. 1, when the five permanent members of the U.N. Security Council and Germany met with Iranian officials in Geneva over nuclear proliferation negotiations.

The official said that U.S. Undersecretary for Political Affairs Bill Burns also requested information on the welfare and whereabouts of two dual nationals, American scholar Kian Tajbakhsh and Reza Taghavi, a 71-year-old American who has been imprisoned since May 2008 without a trial or formal charges…”

[Full article]