Kabul: Afghanistan's controversial first vice-president, who has been under investigation and virtual house arrest for months on accusations of assault, flew to Turkey on Saturday for "medical tests", according to his aides and Afghan government officials.

But human rights groups, Afghan analysts and others said they suspect that Abdul Rashid Dostum, 63, an ethnic Uzbek militia leader and former army general, had flown into exile to avoid prosecution, possibly in a deal with the government. He has not been charged with any crime.

Afghan Vice-President Abdul Rashid Dostum is seen weeping during a song rendition on the day of the alleged abduction. Credit:ATV Afghanistan

"Vice-President Dostum does have a judicial case pending, but he has gone to Turkey for health tests. We pray for his health and return," Shah Hussain Murtazavi, a spokesman for Afghan President Ashraf Ghani, told journalists on Saturday afternoon.

Last December, an elderly Uzbek politician named Ahmad Ishchi accused Dostum on national TV of ordering his militia guards to imprison, beat and rape him. The powerful warlord claimed the charges were a political plot, but the incident put Ghani under strong foreign pressure to bring him to justice.