The trio were seen breaking COVID-19 protocols in Durham and were asked to fly back home.
Dubbed the "terrible trio" by the media, the three players were seen breaking the COVID-19 protocols and venturing outside the team bio-bubble in Durham and their photos and video clips without masks were posted on social media.
Sri Lanka Cricket officials said an inquiry into how they left the team's pandemic isolated hotel in England would start after their mandatory two-week quarantine. None will be included in the three one-day internationals and three T20I games to start July 13 against India.
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"They are likely to get a minimum one-year suspension if found guilty of several breaches of their contract," one SLC official told AFP.
The trio was also pulled out of the three-match one-day international series against England after Mendis and Dickwella were seen smoking in the streets of Durham, where they were based ahead of the ODI series.
In a second video on social media, Gunathilaka is seen joining the pair, violating the coronavirus rules of their stay.
Sri Lanka has already lost the first ODI match after being whitewashed in the 3-match T20I series before, which was their fifth consecutive series defeat, and saw their fans launching a campaign to shun the team on social media.
(AFP inputs)