According to The Times, an extradition request is one of the options under consideration, while the final decision has not been taken yet.
Another source, in contrast, told the newspaper that extradition has not been on the agenda.
The Guardian newspaper reported on Monday that the UK Crown Prosecution Service (CPS) had completed the process of compiling the extradition request for two suspects and is ready to file it. The UK Foreign Office dismissed the reports as a "speculation."
READ MORE: UK Foreign Office: No Plans to Ask Russia to Extradite Salisbury Suspects
On March 4, former Russian double agent Sergei Skripal and his daughter Yulia were found unconscious on a bench at a shopping center in Salisbury. The United Kingdom and its allies have accused Moscow of having orchestrated the attack with what UK experts claim was the A234 nerve agent, without presenting any proof. Russian authorities have strongly refuted the allegations as groundless. Both Sergei and Yulia were later discharged from the hospital.