P Girija, representative of National Commission for Scheduled Castes, collected details from investigators who probed the case and took statements from the Dalit sisters.
The state SC/ST Commission Chairman Justice P N Vijayakumar and other members also met family members of the women.
According to CPI(M)'s complaint, the women had barged into the party office here and attacked one of their activists recently.
However, the siblings dismissed the charges and said they did not attack anybody but only questioned the Left activist who abused them by referring to their caste.
The duo were released next day after the National Commission for Scheduled Caste intervened.
Anjana had allegedly attempted suicide after her release and is presently undergoing treatment at the Indira Gandhi Hospital at Thalassery.