The BBC has more.
Mr MacDougall held the seat of Glenrothes, which neighbours Gordon Brown's, at the last General Election with a majority of nearly 11,000.
Our consolations to his family.
10.30am:
"Speaking after the sad death of John MacDougall MP was announced, David Mundell MP, Shadow Secretary of State for Scotland, said:
"John was a kind and decent man who dedicated to the service of the people of Fife, with distinguished service both in Parliament and local government. I have greatly admired the way in which he has borne such a debilitating illness with enormous courage. My thoughts are with his family and friends at this difficult time.""