MOSCOW, June 26 (RIA Novosti) - Russian investigators have charged a Chechen woman with involvement in the high-profile kidnapping of the son of an executive at Russian oil giant Rosneft.

The son of Mikhail Stavsky, Rosneft vice-president, was freed last week, nearly three months after he was forced into a BMW in broad daylight outside the Russian State Oil and Gas Institute.

The woman Zarema Datayev, from the Chechen capital Grozny, was detained last Saturday.

"In line with investigators' request, Datayeva will remain in custody," the Investigation Committee said on its website.

Datayeva faces up to 20 years in prison if convicted on kidnapping charges.

The committee has not released any further details of the case.

The case has been shrouded in mystery, with few comments available from police or investigators. Deputy Prime Minister Igor Sechin heads the Rosneft board of directors.

Media earlier cited investigators as saying they were looking into a number of motives, including ransom and attempts to put pressure on the victim or his family.