The government wants to do a test landing before a presidential election on September 23.
He was offered freedom if he joined the government and a chance to leave the Maldives with his family.
Mohamed Nasheed said Saudi Arabia supported violent extremism in the Maldives.
The ruling party's VP pick has raised eyebrows in some quarters.
Clerics said it was a 'golden opportunity' for advancing Islamic traditions.
Dr Shaheem previously served as Islamic minister in President Yameen's cabinet.
Two former attorneys general, a minister at the president's office, and the former Islamic affairs minister have been under secret police surveillance for nearly a year...