The Sri Lanka Campaign for Peace and Justice claims certain hotels, airlines and attractions around the country - including a number of wildlife sanctuaries - have political or financial links to the alleged perpetrators of human rights abuses.
It has launched a campaign called "Think Again" which warns tourists of a "culture of impunity" in Sri Lanka, a country in which "continued abuses thrive".
The non-profit group listed a number of tour operators on its website who it said were currently offering holiday packages through businesses that "are of concern" and suggested alternatives for travellers to try.
Fred Carver, from Sri Lanka Campaign for Peace and Justice, said he wanted the tourist industry to "open its eyes to what is going on in Sri Lanka and to realise that it is being used in the government's scheme to disguise militarisation as development."
The campaign has found support from UK charity Tourism Concern which said the claims highlighted "the need for tour operators to take a rights-based approach, which means conducting human rights due diligence on the destinations and packages they offer, in order to identify where these may be linked to rights abuses or abusers."
Tourism Concern said the solution was not for tourists to avoid Sri Lanka, however, as many locals are highly dependent upon tourism for jobs and livelihoods. "Tourists could seek out smaller family-run hotels or guesthouses, or community-based tourism schemes," a spokeswoman suggested, "such as those featured in Tourism Concern's Ethical Travel Guide."
The Association of British Travel Agents (ABTA) and tour operators contacted by Telegraph Travel said they took the allegations seriously.
Speaking on behalf of the tour operators, Nikki White, ABTA's Head of Destinations and Sustainability, said: "ABTA and its members take our responsibilities with regards to human rights very seriously and we work with a number of organisations, including Tourism Concern, to monitor, identify and address any issues in travel destinations."
She added that ABTA had no experience of the Sri Lanka Campaign for Peace and Justice but said it would "look more closely into this organisation and the points that have been raised."
Virgin Holidays, one of the UK operators listed on the campaign website as using businesses that "are of concern", said: "We encourage all of the hoteliers we work with to join the Travelife certification scheme – run by ABTA – which helps them to manage their environmental and social responsibilities."
A spokesman for Kuoni, another operator listed, said it has started conducting a "human rights impact assessment" in partnership with Tourism Concern, which it plans to standardise and roll out to various destinations.
The Telegraph, London