Gaur passed away due to cardiac arrest in Bhopal on Wednesday morning. He was 89.
Modi said Gaur served people for decades and transformed the state.
"From Jana Sangh days, he worked constantly to strengthen our party. As Minister and CM of Madhya Pradesh he undertook many efforts to transform the state," the PM wrote on Twitter.
"Saddened by his demise," he added.
Gaur served as the Madhya Pradesh Chief Minister from 2004-2005.
(Published 21 August 2019, 04:02 IST)