Two-time world champion in Thai kickboxing, Valdet Gashi, who had left his family in Germany to join the Islamic State was killed by Isis for attempting to run away from Syria.

Reports of Gashi's death had emerged a few weeks ago, after his family told a Swiss TV channel that he had died in Syria, though the reason of his death was not clear.

The Syrian Observatory for Human Rights, a monitoring group that highlights Isis activities in Syria, has said that Valdet Gashi was arrested while trying to flee from Aleppo in Syria with 'another group'.

The Thai kickboxing champion was then jailed in the city of Manbej in Syria and later killed by Isis, the monitoring group said, citing 'reliable sources'.

However, SOHR also said that it received news from another source who claimed that Gashi was still alive and was trying to escape from the Islamic State.

Gashi, a 29-year-old of Albanian descent, had reportedly left Germany to travel to Syria in January this year, leaving his family, including two daughters, behind.

"If I die while doing good, I of course will be glad," the Mixed Martial Arts (MMA) fighter had said in an earlier interview, justifying his decision.

However, the SOHR has now reported that Gashi was 'shocked' by Isis after he moved to Syria and had been attempting to travel back to Germany right from the first month after joining Isis ranks.