A man who allegedly doused himself in petrol and lit himself on fire inside a Melbourne bank, injuring 26 people, has been charged nearly three months later.

Myanmar refugee Nur Islam allegedly set himself alight inside Commonwealth Bank's Springvale branch on November 18 and has been under police guard in hospital since.

The 21-year-old, who was critically injured in the fire, was driven to police headquarters today to face questions from detectives.

Police said he is facing 90 charges but have not released further details.

Mr Islam has been in Australia since 2013 and was on a bridging visa when the alleged crime was carried out.

Nur Islam has been charged over the alleged arson attack. (Supplied)