A double agent allegedly recruited by MI5 and MI6 was a British passport holder, according to American media reports.
More than 30,000 off-duty police officers march through central London in protest at cuts aimed at reducing their numbers by 20 per cent.
Tens of thousands of civil servants are striking on Thursday in a dispute over the government's public sector pensions reforms.
The Unite union is given until 21 May to decide whether to accept a final set of proposals drawn up in a bid to prevent a strike by fuel tanker drivers.
A deal has been drawn up aimed at resolving the fuel tanker drivers dispute raising hopes that strikes can be averted.
Haulage firms and Unite union negotiators meet at Acas in the hope of averting a strike by tanker drivers.
Unite insists that the fuel-tanker drivers' strike not about pay. But that hasn't stopped rumours that the union's demands include a 27 per cent pay hike for drivers, and it hasn¿t stopped Conservativ
Independent petrol retailers turn on the government for encouraging panic buying of fuel, describing its approach as "ill-conceived" and criticising ministers for failing to engage with the industry.
Having previously told drivers to top up with petrol ahead of a possible tanker drivers' strike, the government is now saying there is no need to queue at forecourts.
Prime Minister David Cameron urges petrol tanker drivers to withdraw their strike threat, but the Unite union will only agree to postpone industrial action until after easter.