After reviewing CCTV footage of the incident, Merseyside police yesterday arrested and questioned a boy from the Fazakerley area of Liverpool, who cannot be named because of his age, on suspicion of robbery. He was released on police bail yesterday pending further enquiries.
The group, described as wearing dark clothing and balaclavas, threatened Dr Dharmana and stole his keys and Rolex watch before stealing his black Audi TT car.
The car was later found less than a mile away in Sonning Road, Walton.
Anyone with information can contact the police on 0151 777 6064 or Crimestoppers on 0800 555 111.