Thailand don collect back di elephant gift wey dem give Sri Lanka for 2001 onto say di animal dey suffer and na sometin wey don cause kasala between di two kontris.
Di 29-year-old elephant wey dem dey call Muthu Raja return to im original kontri on Sunday on top aeroplane wey cost $540,000 to hire.
Thai goment demand di return of dia animal afta dem receive claims say dem dey torture am for wia dem keep am for one Buddhist temple.
Sri Lanka prime minister say e don formally apologise to di Thai king over di mata.
The 4,000kg (8,800 pound) elephant undergo airlifting to Chiang Mai inside one specially arranged steel cage and na four Thai handlers and one Sri Lankan zookeeper accompany di animal.
Dem say di animal go undergo hydrotherapy to treat injury on im front left leg.
Both Sri Lanka and Thailand dey consider elephants to be special animals.
Na for 2001, di Thai royal family gift three elephants, including Muthu Raja, to Sri Lankan goment for dem to train dem as carriers of religious relics.
Dem place Muthu Raja wey dem return for di care of one temple in di south of di kontri.
Animal rights groups say dem dey make di elephant to work with one logging crew for di temple, and dat na wetin make di animal develop stiff leg from a long injury wey dem no treat on time.
One activist group Rally for Animal Rights and Environment (RARE) wey dey stay for Sri Lanka bin lobby last year for Thai officials to chook mouth for di elephant mata.
Afta dem say dem spend months dey try get di Sri Lankan goment to act, di group founder Panchali Panapitiya tok.
Ms Panapitiya say di failure of Sri Lankan wildlife officials to act don bring ‘shame’ to dia kontri, The Independent bin report.
RARE don also petition say make authorities prosecute pipo wey dey responsible for di elephant suffer-suffer and injuries.
Sri Lankan wildlife minister Pavithra Wanniarachchi tell local media say Thailand bin show seriousness with dia demand say Muthu Raja must be returned afta dia ambassador for Sri Lanka confam di animal to be in poor health during im visit last year.
Muthu Raja dey in pain and wen dem remove am from di temple last November, AFP report. Activists claim say na di main handler cause some of di wounds on di animal body.
Dem bin temporarily transfer Muthu Raja to Sri Lanka National Zoological Garden and most of di wounds bin don heal in recent months.
Sri Lankan Prime Minister Dinesh Gunawardena tell im parliament for June say e don tok about im regret to di Thai king Maha Vajiralongkorn over Muthu Raja alleged abuse and don re-establish trust between di two kontris".
Di Thai goment stop to dey send elephants overseas about three years ago following protests from activists, Thai environment minister Varawut Silpa-archa na im tok am last month.
Bangkok wildlife department say e dey monitor di condition of all di Thailand elephants wey dem don send overseas.