Mariah Carey held a lavish celebration for her baby twins' first birthday.

The singer and husband Nick Cannon showed they were proud parents as they posted party photos on Moroccan and Monroe's personal website, Dembabies.com, from their first birthday celebration.

The siblings - dubbed Roc and Roe for short - were seen dressed to the nines as they played with various toys including a mini Ferrari, a rocking horse, a miniature white piano and a doll's house, with Roe even showing an early penchant for bling as she touched her mum's dazzling diamond necklace.

Mariah dressed in a floor-length gown in a neutral hue for the special occasion on April 30, while Nick - who was diagnosed with an autoimmune disease called lupus nephritis in March - wore a white suit.

The married couple kept up their tradition of renewing their wedding vows as they celebrated their fourth wedding anniversary on the same date.

"I have to do it every single year. If you were married to Mariah Carey, you'd want to marry her every year too! I just have to keep doing it to make sure it's real," Nick explained.