THE Queen officially welcomed King Abdullah of Saudi Arabia to Britain today amid burgeoning controversy over the Middle Eastern ruler's stay.

The monarch and the Duke of Edinburgh greeted the leader on Horseguards Parade at the start of the first state visit to the UK by a Saudi king for 20 years.

Prime Minister Gordon Brown, Home Secretary Jacqui Smith and Minister for the Middle East Kim Howells joined dignitaries on the dais for the ceremonial welcome of the "Custodian of the Two Holy Mosques".

Saudi human rights records and the king's recent remarks about the July 7 terror attacks have heightened controversy over the trip.

The king arrived at the central London parade ground with the Prince of Wales.

He shook hands with the Queen, who was dressed in a claret matching hat and coat, and spoke to her through a translator.

Amid pomp and ceremony, the mounted Queen's Life Guards in their white plumed helmets and red tunics lined Horseguards.

A uniformed Sir Ian Blair, head of the Metropolitan Police, who led the force through the London bombing atrocities of 2005, also greeted the king with a handshake and a smile.

King Abdullah insisted in a recent BBC interview that Britain was not doing enough to tackle terrorism.

The Foreign Office was forced to rebut his claims that the Saudi authorities had provided information which could have averted the July 7 attacks.

Meanwhile, human rights groups have urged the Government to put pressure on the king over allegations of torture and subjugation of women in Saudi.