Waseca, Minn., native  Jerry Krause went missing April 7 after the small plane he was piloting went off the radar during his solo flight from South Africa to Mali. Krause, a missionary, spent 25 years living in Africa doing missionary work with his wife, Gina. They spent 16 of those years in Mali, Krause’s destination.

As The Washington Post reports, Krause’s aircraft went off the radar somewhere near the Gulf of Guinea, after a control tower on the small island of Sao Tome claimed it lost power during a tropical lightning storm. Family members allege that officials continue to change their story and various details about the incident remain inconsistent and suspicious. For one, search crews have yet to uncover a trace of Krause’s aircraft, which officials say would have been found or washed ashore if it had crashed. Krause’s family now believes there’s a legitimate chance he may have been taken hostage after an impromptu landing and forced to fly for guerilla members of local resistance groups.

As BBC News explains, Mali has been in the grips of a major political crisis since last year, when al-Qaeda fighters staged a coup in attempts to spread Islamic law. The area has also been a target for pirates and hijackers; this past February a British ship was seized for its cargo.The recent hostility has forced many charities to flee the area; the air service Krause had been serving under as a missionary pilot backed out in 2009, but Krause continued to do his work.

Krause’s last contact was apparently with the control tower at Sao Tome island, and friends and family are asking that officials in the area cooperate in his search and rescue. The family even recently sent a translator there in hopes of obtaining information. Meanwhile, they also ask for prayers and support to help return their beloved husband and father.