The action comes in the wake of a controversial poster being pasted by supporters of Karunanidhi's Madurai-based son M K Alagiri in that town, making critical remarks in the context of the party's general council held last month in Chennai.
Alagiri did not attend the December 15 meeting.
The poster carrying a photo of Alagiri and his younger brother Stalin sharing the dais with Karunanidhi purportedly showed the party's general council being held on January 30, which is Alagiri's birthday, at the DMK headquarters in Chennai.
Subsequently, the Madurai Urban unit was dissolved on Saturday as some functionaries were found acting against the party interests and despite warning from Karunanidhi, DMK general secretary K Anbazhagan said in a statement.
Anbazhagan said a temporary committee has been formed with G Thalapathi, believed to be a Stalin supporter, at the helm of affairs. It has six other members.
Differences between Alagiri and his Chennai-based younger brother Stalin are well-known with both sparring on the issue of who is the political heir apparent to Karunanidhi.
While the 90 year-old DMK chief had at times hinted that Stalin could well be his successor, Alagiri had challenged that, asking if the party was a "mutt" where a senior pontiff could anoint his junior.
Prior to the 2011 elections when the AIADMK stormed to power, Madurai was believed to be Alagiri's bastion with the leader enjoying tremendous clout in the southern districts. He had been earlier made the party's Organising Secretary, South.
But since DMK's rout in the 2011 elections and the party's withdrawal from the Congress-led UPA cabinet over the Sri Lankan Tamils issue last year, the 63 year-old Madurai MP, a former Union Minister, has been maintaining a low profile.
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