London, Dec 3 (IANS): The sister of an Indian-origin man who skipped bail in Britain to join the Sunni radical group Islamic State (IS) in Syria has urged him to return to the country.

Abu Rumaysah, 31, born Siddhartha Dhar to a family of Indian origin, had posted a photograph of himself on Twitter last week, holding his baby son in one hand and an AK-47 assault rifle in the other with the hashtag #GenerationKhilafah, meaning those who live under the self-proclaimed caliphate, The Daily Mail reported.

Dhar reportedly fled Britain while on bail in September after being arrested in London with radical cleric Anjem Choudary.

"My kind and generous brother had changed beyond all recognition since converting to Islam and being radicalised," his sister Konika Dhar said.

"My brother was misguided if he was taking his moral guidance from the radical cleric," said Konika.

"I was absolutely devastated and my heart goes out to my brother because I know it's not like him," she added.