The Washington Post newspaper claimed his real name was Mohammed Emwazi, a computer programmer from west London.
Chelsea have more than doubled the size of their sponsorship deal in a new £40 million a year agreement with Japanese firm Yokohama Rubber.
The deal has smashed the club's previous record, and dwarfed the agreement with current sponsors Samsung - which is worth £18 million a year.
The company's logo will be on shirts from next season from youth through to senior teams.
It means Chelsea's earnings will be the second highest of all English football clubs - behind only Manchester United's £53 million a year deal with Chevrolet.
CAGE, the UK-based advocacy group who had contact with Mohammed Emwazi, the man identified by US security sources and US journalists as Mohammed Emwazi, are holding a press conference on their dealings with him. UK Editor Rohit Kachroo Kachroo reports.
Asim Qureshi, a research director from advocacy-group CAGE, said the Mohammed Enwazi that he worked with was kind, generous and gentle.
Qureshi said the Washington Post recorded his comments incorrectly, and that he said there was a striking similarity between Enwazi and 'Jihadi John', but did not say for certain. He said:
"While I think there are striking similarities, I can't be 100% sure certain. He has got a hood on, come on guys, the guy has a hood on his head."
A train filled with smoke ground to a halt in a tunnel in north London today after developing a fault. The East Midlands Trains service which was destined for St Pancras got as far as West Hampstead when a passenger activated the alarm.
Speaking to the Evening Standard, one passenger said some people began crying:
East Midlands Trains said there was no danger to passengers:
Think of potential candidates for London mayor and Sol Campbell won't be a name that springs to mind, until now. The former Tottenham and Arsenal player has big ambitions to replace Boris Johnson.
Speaking to The Sun, Campbell said:
Speaking previously to The Guardian he said:
The widely reported identity of so-called "Jihadi John" is accurate and correct, researchers say.
The White House and Downing Street have so far refused to officially confirm whether Mohammed Emwazi is the Islamic State militant featured in a series of brutal beheading videos.
A statement from the International Centre for the Study of Radicalisation (ICSR) at King's College London said: "We believe that the identity and name published by the Washington Post and now in the public realm, to be accurate and correct."
The statement added: "British fighters have clearly demonstrated that they are not in this conflict to take a back seat. They are full participants in this war, operating as suicide bombers, hostage takers, and executioners."