Justin Bieber performs at India's mega wedding

Justin Bieber has become the latest in a string of international stars to perform for the son of India's richest man and his wife-to-be as they celebrate their upcoming wedding.

The Canadian singer flew in to perform for Anant Ambani and Radhika Merchant - along with their guests - in Mumbai at the weekend.

He had a lot to live up to. The couple's first pre-wedding party featured Rhianna, while the second - a cruise around the Mediterranean - had performances from 90s teen heartthrobs The Backstreet Boys, singer Katy Perry and Italian tenor Andrea Bocelli.

So it is with bated breath that Ambani wedding-watchers - of whom there are now legions around the globe - await news of who will perform at the actual wedding itself this weekend.

Rumours swirling on the internet suggest it could be Adele, but the family are remaining tight-lipped.

No expense is being spared on the wedding of Mukesh Ambani's youngest son, putting it in a different league from even the most extravagant of Indian weddings. It outshines even his daughter’s nuptials, which featured a headline-grabbing performance by Beyoncé.

Last weekend Anant Ambani and Radhika Merchant celebrated their sangeet ceremony - a night of music and dance ahead of the wedding ceremony. In typical style, the Ambanis went above and beyond what would usually be expected by guests.

It saw Mukesh Ambani, the head of Reliance Industries, with an estimated net worth of $115bn, according to Forbes, and the rest of the family take to the stage in their own choreographed dance to Bollywood star Shah Rukh Khan’s hit song, Deewangi Deewangi.

It was also another chance for wedding-watchers to pore over the outfits worn by the guests - which included some of India's most glamorous stars wearing dresses by the country’s top fashion designers.

It seems as much as the pre-wedding events have been concerts, they have also become catwalks, with stars sharing professional shots on their social media accounts ahead of the parties.

The cost of the three parties to date is not known. It was rumoured Rhianna had been paid $7m (£5.5m) for her performance, while the figure suggested for Justin Bieber is said to be $10m.

Exactly what the weekend's three-day event holds remains to be seen. For some in India, it will come as a relief that the wedding and its extravagance is over, while those in Mumbai will be hoping it does not make the city’s famously bad traffic any worse.

Radhika was keeping her cards close to her chest when she told Vogue US last month that planning was "going great", adding: "I’m very excited to be married."