"He gets a lot of solace from doing it. Just being able to physically see people and pray with them during lockdown - it's what the clergy has been doing the length and breadth of the country.

"There is some personal risk but he doesn't really think about that. He just thinks this is what Christians should be doing, helping others."

Last week, the Archbishop is thought to have prayed with the family of a critically-ill six week old baby, who wasn't being treated for coronavirus.

He also prayed with a female patient suffering with severe symptoms of the disease in intensive care.

On another occasion, a patient who he was praying with recognised him and called their relatives so he could pray with them on the telephone.

He is not understood to have come into contact with the Prime Minister, who was admitted to St Thomas' intensive care unit on April 6 for three days.

The source added: "Sadly their time at the hospital did not overlap."

The Archbishop was invited to help out by Mia Hilborn, who has been Hospitaller and chaplaincy team leader at Guy's and St Thomas' since 2001.

The Rev Hilborn said: "We are very thankful to the Archbishop of Canterbury for taking the time to visit patients at St Thomas' Hospital. Some of these patients are very unwell and having the support and blessings of the Archbishop at a difficult time has meant the world to them.

"We are also grateful for the support he has given to staff who are doing an incredible job during this challenging time."

It comes after the Telegraph revealed on Tuesday that the clergy will begin streaming services from the churches this week.

For more than two months, places of worship and religious buildings have remained closed in a bid to curb the spread of the virus.

However, last week the House of Bishops decided that guidance banning clergy from entering their churches may be modified by individual dioceses.

Writing in the Telegraph, the Bishop of Chelmsford, the Rt Rev Stephen Cottrell, the Archbishop of York designate, confirmed that some vicars will be streaming services from their churches in the coming days. He also claimed Christianity and the Church of England would emerge "stronger" following the pandemic.

It followed a reported rebellion by some vicars against guidance issued by Bishop Welby warning the clergy that they could not enter churches for solo prayer or to film a service - despite provision for this in the Government's lockdown rules.

On Easter Sunday, the primate of all England and the head primus inter pares of the worldwide Anglican Communion delivered a virtual sermon from the kitchen of his Lambeth Palace flat, filmed on his iPad by his wife Caroline.

Ordinarily he would have been presiding before a congregation of 1,500 people at Canterbury Cathedral on Easter Sunday morning but instead he welcomed his flock "from the kitchen of our home on Easter Day," as he praised the 'heroism' of frontline workers in the face of the global pandemic.

He added: "Our prayers today are especially with those who are suffering, with those who care for them, and for all who mourn."