Retired Pope Benedict XVI has denied speculation that he was pressured to resign, saying the decision was made by him and him alone.

In a letter to La Stampa newspaper Benedict called speculation he had been forced from his post 'absurd' ahead of the first anniversary of the resignation on Friday.

The Pope Emeritus has also fended off allegations that he is still active within the church, leading a faction of the Curia who are unhappy with Pope Francis's sweeping new reforms.

Benedict announced his decision to resign on Feb. 11, 2013 and formally stepped down on Feb. 28, becoming the first pope in 600 years to do so.

Two weeks later, Francis was elected the first non-European pope in 1,300 years.

Benedict said at the time that he was stepping down because he no longer had the physical and spiritual strength to run the 1.2 billion member Church and that his decision had been taken in full freedom.

At the time he promised to live a cloistered life ‘hidden from the world’ and has not spoken in public since.

However, some Vatican watchers claim that his resignation was not 'valid' a situation and that Benedict continues to lead as a ‘shadow’ Pope.

Benedict has kept his Papal name, lives in the Vatican and continues to wear pontifical white, though he says this is because there were 'no other clothes available' when he stood down.

Earlier this month Italian newspaper Libero ran a long story reviving speculation that Benedict may have been forced to resign because of scandals in the Vatican.

In 2012, Benedict's butler was arrested for leaking sensitive documents alleging corruption among Vatican prelates and irregularities in Vatican finances.

Italian media at the time reported that a faction of prelates who wanted to discredit Benedict and pressure him to resign was behind the leaks. The Vatican has always denied this.

Libero also suggested that Benedict chose to continue to wear white because he still felt like he was a pope.

Benedict, who lives in near-total isolation inside a former convent on the Vatican grounds, was also asked about this and responded:

In an interview earlier this month, Benedict's personal secretary, Archbishop Georg Ganswein, said the former pope saw his main function now as helping the Church and his successor through prayer.

Benedict has responded to a few letters in the past year and has appeared in public only a handful of times.

The latest was last Saturday when he attended a ceremony in St Peter's Basilica when Pope Francis created new cardinals.

In his letter he wrote: 'There is absolutely no doubt regarding the validity of my resignation from the Petrine ministry.

'The only condition for the validity of my resignation is the complete freedom of my decision. Speculations regarding its validity are simply absurd.'

On Saturday there were visibly shocked faces when Benedict left his monastic home to attend a ceremony creating nineteen new cardinals.

'As the anniversary of his resignation approaches, some have suggested that Benedict XVI’s resignation may have lacked validity and that he is therefore still playing an active and institutional role beside the reigning Pope,' veteran Vatican journalist Andrea Tornielli explained.

The Pope Emeritus also sought to justify his continued use of his Papal name and clothing, writing in the letter to newspaper La Stampa: 'I continue to wear the white cassock and kept the name Benedict for purely practical reasons.

'At the moment of my resignation there were no other clothes available. In any case, I wear the white cassock in a visibly different way to how the Pope wears it. This is another case of completely unfounded speculations being made.'

Benedict XVI caused shockwaves around the globe when he announced his plan to step down on 11 February 2013, telling cardinals: 'I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of the Petrine ministry.'

It took effect on 28 February when the cardinals met to begin the process of electing his successor, Francis.