How do you keep a celebrity wedding secret?

He's behind you... Jessica Chastain was upset by press intrusion at her wedding

Celebrity weddings appear to be everyone's business, regardless of whether the two people getting married actually want the world to see them tying the knot.

Jessica Chastain, who married earlier this month, had been intent on keeping prying eyes away.

But her ceremony was gatecrashed - by a helicopter and a long lens.

The photographs were widely shared, prompting the Oscar-nominated actress to ask fans to respect her privacy.

She tweeted: "I am going to ask you to please stop sharing the photos. Helicopters disregarded a no-fly zone and took those pics during the ceremony. Every time I see them I'm reminded of the insensitivity of that incident."

George and Amal Clooney sold photos of their wedding to the press

When George Clooney and his wife Amal married in 2014, they kept the press pack at bay by selling photographs to Hello! and People magazines, reportedly giving the fee to charity.

Brad Pitt and Angelina Jolie did the same when they married a month earlier.

But what if, like Jessica, celebrities would rather not allow the world to see their private, personal day?

Celebrity wedding planner Lisa Vorce, who was behind John Legend and Chrissy Tiegen's wedding in 2013, says the paparazzi are "ruthless". She told us how she manages to keep the press where she wants them - at a distance.

Chrissy Tiegen and John Legend, pictured earlier this year, married in 2013

How easy is it for celebrities to keep their wedding arrangements secret?

It's not easy! You have to be incredibly stealthy about the process and unfortunately you have to operate from a "trust no-one" perspective.

What do you think about measures such as asking guests to hand in their mobile phones and sign non-disclosure agreements on entry - is that necessary?

Unfortunately - yes absolutely. It is very helpful (and necessary).

Guests are usually understanding and willing to do whatever it takes to help the wedding couple celebrate their big day in peace.

It can cause some stress (for example, guests might say, "what if my child needs to reach me?") but that is easily mitigated by having an emergency contact number (i.e. us) and phones on site for emergency calls out (under security supervision).

Jessica Chastain asked fans not to share paparazzi photos of her wedding

What about visiting venues, buying clothes, hiring people to help, choosing food, decor, music - how can things like that be kept out of the public eye?

Aside from trying on the wedding gown, we are able to do the majority of the planning and production without the vendors having face-to-face contact with the client.

Because I specialise in destination weddings, that's typically our norm anyway - so it's not outside of our typical operations.

We use aliases for the clients on all vendor contracts, send videos of venues, sample floral mock-ups, etc. I don't want to disclose too many of our strategies - let's just say diversion techniques and non-disclosures are involved.

Is it better for celebrities to maybe sell one wedding picture to a magazine for charity in order to keep the press happy, rather than blocking all images?

One image is better than none - but I think it's human nature for the public or fans to always be after more.

Is it common for wedding planners to be asked to sign non-disclosure agreements when working for famous people?

Yes - without exception.

Jessica Chastain had a helicopter taking photos from a no-fly zone - have you encountered any tricky behaviour from the press while trying to organise a wedding?

Yes - the paparazzi are ruthless.

However, there's always a way to combat the intrusions. For example, at one of my celebrity weddings we had paparazzi in boats trying to capture images of the wedding.

Our security team disbursed our own boats to create choppy waves while flashing lights at the paparazzi cameras. They made it nearly impossible for the paparazzi to get a focused image.

How do you manage to keep the wedding feeling celebratory while dealing with possible press intrusion?

We shelter the guests and clients from everything to the best of our ability. Our job is to take care of things before it impacts the client or the guest experience.

We plan for all scenarios, have counter-strategies in place, and have an incredible security team.

The nature of weddings are celebrations of love - there are grandmothers and family members and great friends who are so happy for the wedding couple - all of those positive, heartfelt emotions rise above press intrusion.

What is your advice to celebrities wanting to keep their celebrations private?

1) Stay off social media, and 2) Take a trip to a beautiful place where you don't want to get married and say you would love to get married there!

You famously organised John Legend and Chrissy Tiegen's wedding - what did you enjoy most about doing this and did you learn anything from it?

I most enjoyed that John and Chrissy trusted me and gave me artistic licence to design something that was a reflection of them.

Their wedding was full of joy, music, beauty, friends, and family - all things that are truly a part of their daily lives.

I remember one guest said to me: "This is the best day of my life, and it is not even my wedding!" That was a lovely testament to the joy of that day.