Police said Ulaga Tamizhar Peramaippu (World Tamils' Federation) President P Nedumaran, who played a key role in setting up the memorial at Vilar village, and several others were arrested when they staged a protest without proper permission.
Officials said a notice board was put up at the site that the area was part of the highway and should not be encroached.
However, later some miscreants removed the board, leading to tension. Fifty persons were arrested for allegedly removing the board.
The memorial, put up by a trust, was declared open on November 6 after the Madras high court directed police to grant permission for the three-day inaugural function.
Officials said the members of the trust after giving assurance to the high court and the government that they would not encroach the government and not cause any hindrance to the Public had violated their assurance.
They had also misinformed the court that the entire complex was in private land, the officials said adding encroaching government land could not be tolerated.
Besides Nedumaran, M Natarajan, husband of Tamil Nadu Chief Minister Jayalalithaa's close aide Sasikala, was among those involved in setting up the memorial.
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