Kate Middleton
Kate Middleton (l) in the Orla Kiely dress in February last year (Reuters)

Kate Middleton and Prince William have visited ex-offender charity Only Connect in London's Pentonville Road to learn about how it helps former prisoners and young people at risk of offending.

The Duchess of Cambridge wore the same Orla Kiely dress she wore to The Art Room in February 2012. The dress sold out within minutes of her appearing in it at the engagement in Oxford.

The royal couple arrived at Only Connect's head office for a tour of the building and met charity workers.

They then went on a tour of two charities that are based at the office - Handmade Alliance and BounceBack - both of which also work with former offenders.

Kate Middleton
Kate and William had a tour of the Only Connect office on Pentonville Road (Reuters)

Handmade Alliance trains prison officers to produce textiles for British designers and had prepared a display to show Kate and William. The charity is also about to open its first pop up shop on Carnaby Street later this week.

BounceBack offers offenders work experience, training and employment so they can gain employment after they finish their sentences.

After learning about the charities, Kate and William will watch a drama performance put on by Only Connect.

William is known for his work with ex-offenders, and is the patron of the St Giles Trust, which aims to break the cycle of reoffending by offering housing, training and practical support for former offenders.

Kate Middleton
Kate and William also learned about BounceBack and Handmade Alliance (Reuters)

The prince visited the charity's head office in Camberwell, south east London earlier this month, where he met with staff and volunteers to discuss problems facing former prisoners.

Rob Owen, chief executive of the St Giles Trust, said: "We are thrilled that HRH The Duke of Cambridge is lending his support to the work of St Giles Trust.

"We work with some of the most disadvantaged, socially excluded people in society, so his visit will help highlight the issues and challenges ex-offenders face."

The couple's next official engagement together will be the premiere of Mandela: Long Walk to Freedom at the Odeon Leicester Square on 5 December.