The Easter Sunday suicide bomber who lived and studied in the UK had been under police surveillance in Sri Lanka for years, it emerged on Thursday.

Abdul Lathief Jameel Mohamed, 36, who studied aerospace engineering in the UK for almost two years, was on a Sri Lankan terror watchlist, according to sources close to his family.

The claim raises further embarrassing questions for the Sri Lankan authorities over their failure to stop Sunday’s coordinated attacks on churches and hotels.

The source, close to his brother, said: “He was under surveillance for years.”

It came as footage emerged on Thursday night believed to show Jameel Mohamed with a rucksack laden with explosives, and a suitcase at the Taj hotel in Colombo on Easter Sunday.

In the pictures, obtained by Sky News, he is wearing a baseball cap just like two other suspected bombers pictured on CCTV footage before they struck the Shangri-La hotel.

British intelligence officers are combing through Jameel Mohamed’s connections made in the UK to determine whether he could have been radicalised in this country. He flew into the UK on January 1 2006 and lived in a rented bedsit in Tooting in south London before flying home at the end of September 2007. He returned again in 2008.