Shelar's presence at the May 1 event at suburban Dindoshi surprised many in political circles and invited criticism from Opposition Congress. The event was organised by BJP's youth wing leader Mohit Kamboj.
"It was lack of judgement and mistake (on part of the event organiser). Such a mistake should not be repeated," Shelar told PTI.
Shelar said he has taken serious note of the matter, but clarified no disciplinary action will be taken against Kamboj.
The 56-year-old actor's family has been associated with Congress for long.
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Many in the BJP were critical of repeated paroles and furloughs granted to Dutt while he was serving the sentence at Yerwada jail in Pune in 1993 blasts case. The actor completed his jail term in February.
Kamboj had defended himself when the row erupted.
"I have a long and friendly association with Dutt. I wanted to invite him and got permission from senior party leaders. And what is wrong, if I invited him to be part of the Maharashtra Day celebrations?" he said yesterday.