The suspect being held by UK police on suspicion of the terrorist murder of MP David Ames is named Ali Harbi, Sky News reports.
The channel says that Harbi is a 25-year-old British citizen with Somali heritage, who is not thought to have been previously known to the security services.
British police on Friday night declared the killing of Amess earlier in the day a terrorist incident.
The long-serving member of Parliament was stabbed to death Friday during a meeting with constituents at a church in England, an attack that united Britain’s fractious politicians in shock and sorrow. He was 69 and a married father of five.