LAHORE, Pakistan (AP) — Pakistan's former Prime Minister Nawaz Sharif, who was convicted on corruption charges, has been rushed to hospital from the prison after recent blood tests raised doctors' concerns.

Sharif's doctor, Adnan Malik, says the former premier was taken to hospital late on Monday.

Doctors initially believed Sharif had contracted Dengue fever, which is rampant in Pakistan, but on Tuesday said his low platelet count may have been the results of medication he was taking.

Sharif was sentenced to 12 years in prison on corruption charges and seven years on a separate money laundering charge. He is also under investigation on other corruption allegations. He has appealed the convictions, insisting he is innocent.

Authorities arrested Sharif's son-in-law, Mohammad Safdar, on Monday after he alleged Sharif was being slowly poisoned. Authorities denied this.