The 25-year-old took a hat-trick in his first one-day international against Bangladesh in January, 2018, in Dhaka and played two more Twenty20 internationals on that tour before being sidelined with injuries.
He was caught with 2.7 grams of heroin by police on Saturday and then remanded in custody till June 2, Sri Lanka police said.
"The decision to suspend will remain intact until a full inquiry is conducted by the SLC into the matter," Sri Lanka Cricket said in a statement.
Madushanka's representatives could not be reached for comment.
IMAGE: Sri Lanka fast bowler Shehan Madushanka.
Photograph: Sri Lanka Cricket/Twitter
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