Bilawal Bhutto Zardari's security while studying at the prestigious Oxford University could cost the country's taxpayers as much as 1 million pounds annually.

Police chiefs are said to be concerned that the cost of providing a 24-hour armed guard for Bilawal Bhutto Zardari will be a drain on already overstretched Scotland Yard resources.

A police source told the Sunday Express, "His protection will cost 1 million pounds a year minimum. Talk of it being in line with Prince William's [Images] and other royals is way off the mark, the cost will be stratospheric by comparison".

''The kind of protection he will be afforded is on a par with the likes of Salman Rushdie and KGB defector Oleg Gordievsky," the source added.

The 19-year-old Oxford undergraduate became Britain's most high-profile terrorist target, since author Salman Rushdie, after being named co-chairman of the Pakistan Peoples Party following his mother's assassination in December 2007.

Although Scotland Yard has refused to comment on Zardari's protection, risk assessment has been carried out by a detective inspector, according to the newspaper.

According to the report, Zardari qualifies for the top level of protection, which includes a close protection team of 12 armed officers in two vehicles working eight-hour shifts. All teams are SAS-trained and carry 9mm Glock pistols.

With Scotland Yard resources already stretched, an estimated yearly wage bill of around 500,000 pound will strain resources more.

Royalty and diplomatic protection units are so under-strength that some officers are having to work 40 days without a break.

Tory MP David Davies, a member of the Home Affairs Select Committee, said the wealthy Bhutto family should help foot the bill for Zardari's protection.

Shadow policing minister David Ruffley said, "Of course this young man must receive the protection he needs from terrorists, but I am sure many hard-pressed police who are already struggling against budget cuts might wonder whether the Bhutto family should make a contribution".