According to the newspaper, the UK security services and counter-terror police are now examining the attacker's motives in trying to get a job. Butt considering targeting the tennis tournament is one of the possibilities.
The suspect had previously worked on the London Underground until quitting in October, The Telegraph reported.
On Friday, UK police investigating the London Bridge terror attack arrested a man on suspicion of being involved in preparing acts of terrorism, bringing the number of suspects in detention up to six. Twelve other people who were detained in the wake of the van and knife attack in London were released without charge.