ENRIQUE Pena Nieto, the President of Mexico, begins a three-day state visit to the UK today, which will include a trip to Scotland to sign an energy collaboration deal.

The United Mexican States is the ninth largest producer of oil in the world.

As the 48-year-old leader touched down at Heathrow Airport human rights campaigners staged a stunt outside the Mexican Embassy in London in protest against torture and handed in a petition calling for its end in the Latin American state.

Amnesty International has described torture as being "out of control" in Mexico amid a six-fold increase in the number of reported cases in the past decade.

The rise in torture cases has coincided with the country's nine-year-long "war on drugs", which has also seen over 100,000 killings and over 22,000 disappearances, the human rights group said

Tom Davies, Amnesty International UK's Stop Torture campaign manager, said: "While President Pena Nieto is getting the red-carpet treatment, his police and security services have serious blood on their hands.

"With public officials complicit in drug cartel crimes as well as thousands of torture cases of its own, President Pena Nieto needs to radically overhaul his country's woeful response to this crisis."

During his UK visit, the Mexican President will be accompanied by his wife Angelica Rivera. Today, they will meet the Queen at an official ceremonial welcome on Horse Guards Parade in central London after which they will travel in a carriage procession along The Mall to Buckingham Palace.

The couple will stay at the Palace as guests of the monarch and will attend a glittering white tie banquet held in their honour on this evening.

Tomorrow, Mr Pena Nieto will have lunch and hold talks with Prime Minister David Cameron in Downing Street. He will also meet Nick Clegg, the Deputy Prime Minister, and Ed Miliband, the Labour leader.

On Thursday before he returns home, the President will fly to Aberdeen where he will formally announce a new memorandum of understanding at a meeting with North Sea industry leaders.

The agreement between UK Export Finance and PEMEX, Mexico's state-run fuel conglomerate, will cover a line of credit of up to $1bn with the finance used by PEMEX and its subsidiaries to buy services from UK exporters.

Mr Pena Nieto will also visit Robert Gordon University to meet academics and attend a presentation on the energy sector.

His trip to Scotland will be hosted by Scottish Secretary Alistair Carmichael and Energy Minister Matt Hancock.

In 2009, during a previous state visit, Felipe Calderon, the then Mexican president, also visited Aberdeen.

Mr Pena Nieto's UK visit follows one to Mexico last November by Prince Charles and the Duchess of Cornwall.