Tomar, who was earlier in the Bahujan Samaj Party, joined the BJP in 2011 in the presence of chief minister Shivraj Singh Chouhan and the then party's state unit president Prabhat Jha.
The incident occurred just after the train started from Bhopal, in the AC compartment in which both were travelling.
Upadhayay told HT that Tomar was travelling with his family and was allotted a side upper berth. "I had a lower berth and he forcefully ordered me to exchange the berth, but I refused. Then he started using foul language and misbehaved with me.
It all happened in front of fellow passengers and everyone was watching the way he was behaving," said the collector. "He started arguing with me and even tried to beat me but I managed to grasp his hand. I don't know how I tolerated this hooliganism on the train," he added.
Upadhayay has lodged a written complaint with the Ganjbasoda GRP police outpost, alleging that Tomar was in an inebriated state when the incident occurred. GRP in-charge Mohan Singh Rajpoot told HT: "The collector has handed over a complaint and also demanded a medical check-up of Pushkar Singh Tomar. But the train was about to leave and hence it was decided that the check-up will be done in Katni."
Meanwhile, when HT contacted Tomar, he flatly denied that such an incident had taken place. "I don't want to talk much. I was with my family and I had not done anything on the train," said Tomar.